I recently had the oppertunity to get a nice trad rack for a very good price. I have only done very limited trad climbing, and I am keen to start broadening my horizons.

The gear all came without biners, and looking at it, I bought some BD Neutrinos.

The way I see it is that I can just attach the biner to the sewn sling on the cam, and connect it to the rope, unless I am extending the anchor with a sling. In this case, extending the placement, is it acceptable to just put a biner on each end of the sling, and connect it to the cam? Do I larks foot/ girth hitch the sling around the biners so that they dont move too much?

Now, the hexes, they have sewn slings. Can I just attach a biner to the sling, is that acceptable? Same as above, should the biner be larks footed/ girth hitched around the sling as not to move too much?

Take a lesson with Ross Suter. Every placement is different. Short sling, long sling, quickdraw, directley into cam.
Depending on the crack and which way you heading. And he yells at you if you get wrong

With all respect, if you are asking these kind of questions I think the above advice is good.

trad gear & placements are not rocket science; just logic, a cool clear head & discipline.
for the above questions - i prefer to simply clip the biner; the fact that it can move will optimise drag reduction and also diminish the chance of gear pulling out.
a couple of climbs with an experienced traddie will help a great deal to get your head around these and other issues. invest a bit in it

It's not such a bad question

The most used practice (that I've seen and used) is 1 biner per cam - Nutrinos are perfect. You can rack the hexes on 1 biner and treat them like nuts - extend them with draws. Ideally you want to extent cams too, but since you already have a racking biner on them, you just need a sling and biner. You can carry them over your shoulder. You can obviously also extend them with a draw, but that leaves you with a surplus biner. You can take it with you or just leave it for your second. As Willem said, there's no need to lark foot the biners. For what it's worth I use O rings to keep rope-side biners in place on extendible draws. It makes it neater and easier to handle. Don't do it if you don't know the danger of doing it. On long slings (120cm) I loop the sling around the biner to make it harder to drop it when I take it of my shoulder. Lark foot is only useful for slinging trees and chicken heads. Never use it to attach slings together, you weaken the slings. I don't know if you've seen it, but that aid move on Mt Watkins where Alex Honnold's foot slipped and made everyone watching the video crap their pants - He had a sling connected with a Lark foot to a bolt from which he did the "aid" move. Don't do it! Use carabiners to connect slings to gear or other slings.

The advice to go on a course is good in principle I guess, but I don't think I know anyone who has actually been on one - just saying...

When connecting elements of an anchor chain...

Slings/webbing/wire to carabiner -> OK
Carabiner to rope -> OK
Wire to webbing - NOT OK i.e. do not girth hitch a sling to a nut/hex, wire will cut the sling
Sling to rope -> NOT OK, rope friction will melt webbing
Sling to sling -> NOT OK, especially wide (>10mm) nylon slings girth hitched to skinny (<8mm) dyneema slings ( the skinny sling cuts the fatter sling)
Sling to bolt hanger -> generally NOT OK, although you'll get away with it in an emergency

Further, when clipping sport draws, always use the same carabiner (of the 2 in a quickdraw) to clip the bolts' side. This carabiner will take the abuse from the bolt hanger and the other carabiner will stay nice and smooth on the inside to protect your rope's sheath.

as always, i bow before shorti & hispierreness' ability to explain trad stuff. you guys should think of writing the trad bible for beginners.

http://www.youtube.com/watch?v=uQb4_8PyZBM

haha, how true is that? I just realised my half truth, he didn't aid of it! These things happen with stories told over, details lost in translation, actual facts fading from memory or omitted to make the story better... Anyway, I'm sure someone used it

As long as you don't do any of this you should be fine...

_________________
Happy climbing
Nic