i've got a 661 mullet(cheap and tough), and a Bell Bellistic (fullface) which is real nice but i only wear for downhill or big hits, and i've got a trek something (for xc, it doesn't see much action), I like all my helmets and they are all pretty afforable...and you would probably be fine with a non full face skate style helmet unless you plan on going real big or racing downhill.
I've never ridden with the Flak, Faction, or Baker. The Remedy just seems too big and bulky for me(even for a fullface)...the Faction would probably be real good for you, cheap and a good helmet, i actually almost got one last summer.
for that you could get a decent skate lid and a full face but i'd start with no full face and then you can always get one later...look at the protec ones, the 661 dirt lid, the bell faction, or the giro flak...just go around to some local shops, try them all on and see what you like the best.
remedy are the shit, they are super light and pretty cheap compared to othere helmets. most def get a fuul face though, ive seen some pretty gross shit with faces being torn up. but if not, get a protec skate.
YEAH, THAT JUST HAPPENED
You don't need a full face if you aren't doing serious shit though, and since your just beginning, I'm thinking that might not be the case. Unless you've got the balls to start huckin stuff immediately. I don't.