Try reading through Brimms notes: http://briem.ismennt.is/2/2.3.2a/2.3.2.03.auto.tips.htm

Well, I haven't been autotracing, I've been handtracing... Still, there's some good stuff on that site, so thanks for the link!

Well, looking at the wobbles, I would get some practice with the bézier tools first. I do not mean to offend you of course, but it seems you haven't worked with béziers very often, hence they look wobbly. It really takes some practice to get it right. I could suggest Leslie Cabarga's book 'Logo, Font & Lettering Bible', which has some very easy to understand explanations on how to work with béziers. Things like; minimize the amount of nodes or keeping bézier handles straight as much as possible (i.e. horizontal and vertical), etc. I think it's about US$20, so that's not too bad.

Looking at your PDF, I think you probably have too many nodes, and also nodes with only one bézier handle. It's impossible to get smooth curves this way.

Briem's site is also a nice source indeed, which also discusses béziers a bit I think. If you search google on bézier curves you will probably find more handy tips and tutorials.

Well, I've redrawn the B, C, D and E completely, trying to use as few points as possible. I'm still not completely satisfied with the E but I think I'm on the right track... Am I?

A-E Draft 2: http://typophile.com/files/print.pdf

To give you an idea of what I meant by minimum nodes and horizontal/vertical bézier handles, I quickly traced your D:

Note that I also placed all nodes in extrema, e.g. on the furthest outward/inward points on a line. Or well, I made it quickly, so I tried.

I'll second Quincunx's recommendation for Leslie Cabarga's book. I personally don't think it's a well-designed book, but it has a wealth of very good information. Another book I'd recommend is Karen Cheng's Designing Type.

Cabarga's book is, in my opinion, not well-designed at all. ;)
It actually looks kinda stupid. Although I have the paperback version, which has quite a nice matte black cover with white type. But indeed, the information is good. Especially if you don't know a lot about the subject yet.

Cheng's Designing Type is a good book, although it is more a thurough analysation of different typefaces and their glyphs. Not really on how to design type. Not that that is really a problem, though. :)