Lieutenant
The lieutenant is arguably the most powerful of the four classes in Return to Castle Wolfenstein's multiplayer game. Like the others, he can carry a pistol, a combat knife, and a single grenade, but he can also choose to wield any one of the game's three submachine guns--the Thompson, the Sten, or the MP40--with two clips of ammo. The lieutenant's supposed leadership role stems from his ability to drop packets of ammo for his teammates and from the fact that he can call in two types of devastating attacks to level a certain area of the battlefield. The first such attack is an airstrike, which the lieutenant can summon by tossing a smoke grenade anywhere on the map. A few seconds later, a series of explosions will rock the area immediately around the smoke grenade. His second attack is a mortar strike thatcan hit any target on the map simply by lining it up with the crosshairs of his binoculars. The mortar attack isn't as powerful as the airstrike, but its reach extends to nearly anywhere that falls within the lieutenant's line of sight.

Bruiser Says - Right my Personal favorite class is the Lieutenant.
Because he can supply your Team with the Ammo that they need but iam usually an ammo hog and i give 2 lots of ammo to myself all the time when i spawn then i get to work..
The good thing for this class is that it can Organize "AirStrikes" a very usefull Fragging Feature! :)

X-CaL Says - Its a tough decision for me whether to go for the Lieutenant or the Medic, I quickly scan the teams and try to keep the balance of Lt's to Medics, As for a set loadout of weapons I'm still undecided on which weapon is the best overall, MP40 and Thompson or the Sten are the choices, I wouldnt overlook the Sten, on the downside it overheats fast, but check out how powerful and accurate this baby is. Make good use of the air attacks, and remember to keep your team re-supplied with ammo, particularly any Medics or Engineers you spot respawning. Teaming up with a Medic is an awesome combination.

Medics
A medic revives a fallen comrade. Like the engineer, the medic is a specialized class of infantry who is nonetheless quite capable of defending himself. He's also limited to a pistol, a knife, and a Thompson, but he can carry only a single grenade and he starts with only a single clip for his two-handed gun. To offset his relatively small arsenal, the medic has the unique ability of regenerating his own health up to 123 hit points, which goes quite a long way in extending his survival on the battlefield. The medic can also drop health packs that, when picked up by teammates, will restore 20 points of health. This ability is regulated by his power bar, however. Lastly, the medic can also approach any player who's been mortally wounded (and who hasn't jumped back into the limbo screen) and restore him to half of his total health, which means that a good medic can significantly change the pace of a battle since he can effectively spawn in teammates faster than the reinforcement counter can.

Bruiser Says - Medics are a good class to have.. Especially in the Most Action places
like where the Dynamite has to be planted... but the good thing about this class
is u can throw urself some health and to the other people by pressing the attack key.
but the down points are the ammo to the gun.. so id recommend you find a Lieutenant before you go
out for some action!

X-CaL Says - With the ability to revive and hand out medi-packs, the medic is a must have class, combine the medic with a Lieutenant and you have a class that is fully armed,and has health which re-generates, A good medic keeping a squad of players alive and reviving the wounded (reducing the respawn time) works for both Axis and Allies, the down side of the medic is his initial supply of ammo, so its a good idea to shout for Ammo on respawn and get chasing the Lt's for some ammo.

Soldier
Although the standard light infantry soldiers for the Allied and Axis sides look different from each other, they're both functionally identical. The Allied soldiers don the standard-issue green and brown GI garb of the time, while the German soldiers wear slightly darker uniforms, complete with black helmets and trench coats. Of all four classes in the multiplayer game, the soldier is the most adept in combat since he can equip any of the two-handed weapons that are available to you. Additionally, soldiers can also carry four grenades, a pistol, a combat knife, and three clips for their primary weapon.

Bruiser Says - Well what can i say :) a very popular choise of class
but really i think there the same as a Lieutenant and u might aswell be a Lieutenant
the only Advangtage for this fine class is 4 Grenades :)
and u only have 2 clips of ammo for your gun..

X-CaL Says - Although armed with no special abilitys, the soldier has the biggest array of weaponary to choose from. Sniper rifle, venom gun, and flamethrower, and rocket launcher are all exclusive to the soldier class, armed with these weapons the soldier is a very powerful class, great for taking Gun emplacments or claering out rooms of the enemy fast, larger weapons force slow movement , so switching to the pistol to move is important.

Engineer
These engineers are the game's demolitions experts, and while they can't equip any two-handed weapon other than the Thompson, they do have the unique ability of repairing and destroying hardened emplacements that you'll find throughout the game's levels, and they have an initial health of 110 hit points. Specifically, the engineer carries a toolkit, which when activated and held down for a given length of time will repair gun emplacements that have been damaged by enemy fire. This toolkit can also defuse any dynamite that the enemy places to breach a wall or blow down a door. When defusing a bomb or repairing an object, a timer/health bar will appear that will indicate exactly how much longer you need. The engineer is also the only class capable of carrying and setting dynamite. Like the soldier, he can also carry four grenades, a knife, and a pistol, but he's limited to two clips for his Thompson.

Bruiser Says - This class is a point gold mine of the Allies because u get 5 points for Planting a Dynamite at the Dynamite point and i think 10 when it blows up.. :) but that the good side to these Engineers.
not Really recommended for the AXIS army on the Beachland map only for Disarming the dynamite still you get a few points for doing that :)

X-CaL Says- Crucial at the start of the game, engineers are required to blow up the sea wall to let the troops in to attack the base, they have little ammo, so meeting up with a Lt is a good idea, Axis enginners are crucual for disarming dynamite and require covering fire if they attempt to jump the wall to defuse, once the first task has been completed the engineers server little purpose, unlees they plant dynamite to prevent the enemy camping,

Grenade Tips- (Apllicable to all classes)

Throwing:
Grenades use the horizon line to determine the distance of your throw. If
you want to drop a grenade right in front of you, look towards the ground
and simply tap the 'attack' key. If you want to throw a grenade a great
distance, look above the horizon line at varying degrees. The further above
the horizon, the further you will toss the grenade. However, this does have
a diminishing effect. Looking directly upwards towards the sky will cause
the grenade to return to where you are standing.

Short Fuse:
Both the 'pineapple' and 'potato masher' grenades use a fuse detonator. The
length of which is 5 seconds. You can short fuse a grenade by pressing and
holding your 'attack' key. You will hear 4 'ticks' before it detonates. Let
go of the 'attack' key when you want to release the grenade. An experienced
soldier can time the throw and usually cause a grenade to detonate at the
perfect spot.

Bounce:
Use the bounce of the grenade to your advantage. No, it is not realistic,
but it can come it handy when trying to toss a grenade around corners or
into holes. The bounce can also be used to achieve great distances with your
throw.