Weapon placement and animation

I'm making 3d FPS with lots of weapons. How would I go about placing the different weapons in the players hand and animation them. Would I have to make the weapon separate from the player or would I make them together in the modeling program, or what else would I do.

Also when the weapon needs to be reloaded how could I synchronized the animations of the gun reloading and the players hand moving.

Thnaks