So I broke down and bought BF3 today. This is my first real entrance into the series other than 1943 and I'm still pretty confused. I have unlocked some things but don't always seem to be able to use them. I'm getting the hang of gun attachments, sort of, but I still can't figure out how or where to use some camo that I unlocked a while ago. Anybody know where I can go to learn more or have some tips for a noob?

You go to the customize tab on the menu before spawning to... customize your dude and your loadout and appearance.

Loadout lets you choose what primary weapon and sidearm you want, as well as the 2 gadgets and 1 perk you unlocked. You can only customize the primary weapon with attachments - and that attachment unlock progression is unique to that gun only. If you unlock the red-dot sight on the M16A3, you cannot use it on the AK-74M.

Appearance lets you choose what camo you want.

Back out from the menu manually instead of hitting deploy to make sure the game saves whatever you've selected.

The customisation doesn't always save after you quit I've found personally. The load outs do but not the camo.

Yeah for some reason the camo doesn't seem to stick :/