[gvsu88]

I have an HNMR, and am trying to interpret it, but I'm getting really confused.
Given the molecular formula, C₄H₁₁N
The given values:
4.1ppm,2H,singlet
1.1ppm,2H,quintet
0.9ppm,3H,triplet
3.7,1H,sextet
0.9,3H,doublet

It also gives a note for IR; double peak at 3245 and 3250

I know, based on the IR, and also the 4.1 and 3.7 ppm, that there must be an NH₂ in the molecule.

But how could there be two C-N bonds AND 2 N-H bonds when N is a trivalent atom?
Since there is only one N in the molecule, I don't know what to do with this.

[buRnINGbeND]

i'm not really sure why you think there have to be two C-N bonds.  remember, the IR peaks you're citing are likely NH stretches, not CN stretches, which would be in the 1600 range, and the NMR is giving you data about protons, not carbons.

so if we go off the assumption that 4.1 is in fact an NH2, which is a pretty good assumption considering there's pretty much no other way to get a two proton singlet in this molecule, the rest of it ends up being pretty easy.

the two 0.9 groups have to be terminal methyls, as they're 3H and very far upfield.  since one of them is a doublet, it has to be bonded to a CH, while the other must be bonded to a CH2.
the 3.7 is a CH and is shifted downfield, so is probably directly bonded to your nitrogen.  since it's a CH, it has to also have two R groups attached to it.  it's likely one is a methyl from the previous assignment.
that just leaves one peak accounted for, the 1.1p quintet, which ends up being bonded to both the CH and one of the terminal methyls.  that's 4Hs splitting it, making it a quintet, which matches.

so it's isobutylamine.

[orgopete]

Let us try the irrational approach. How many compounds can you draw that have C4H11N and have an NH2? Okay, let's simplify it again, if it has an NH2, it can only have one C-N bond. If it only has one C-N bond, the carbons are all connected.

Let's try it again. How many butyl amines can you draw? Now, let's analyze them, how many signals does each have? How many signals are present in the spectrum? How many hydrogens are in each signal?

You should be able to identify the compound without looking at the spectrum. Just draw the ratios of the signals. For example, t-butylamine would have a ratio of 2:9 and n-butylamine would be 2:2:2:2:3.