Basically you start up, pick a side, go have fun.
I will now a new step, the picking out.
I think there are two ways to go at this. Either have pre-made classes, or have various, BALANCED weapons to choose from.
(Note all class have a shovel, pickaxe and blocks. Some classes may have more or less blocks however)

SNIPER
Mosin Nagant (Sniper Rifle)
2 Mines ( Boom instant kill if someone gets within a block. Same as a grenade otherwise)
25 Blocks
Pistol

INFANTRY
Rifle
2 Grenades
50 Blocks
Pistol

CLOSE-COMBAT
Trench Gun
3 Grenades
20 Blocks
Knife(?)

HEAVY WEAPONS
Bazooka
1 Mine
Pistol
30 Blocks

For a range of picking out weapons I suggest
PRIMARY:
Rifle
Shotgun
SMG
Sniper Rifle
Bazooka

SECONDARY:
Pistol
Knife
Grenade
Mine
Health Kit(?)
Extra Ammo(?)

Suggestions are welcome!