While there are many good answers to this question, there are a handful of things I haven't seen mentioned or fully explained, so I'll address those points.
Rim Selection
I see a lot of responses talking about why you should not use steel wheels, I haven't seen the most important one, which is that the braking surface on steel rims is far inferior to that of aluminum, and in the rain it's near totally useless.
Assembly Tricks
There's a couple of things I do which I think really aid in both ease of assembly and longevity. Wheels I have built like this have very little problems down the line, and I've personally never seen a spoke break on one.
- Use a drop or two of light oil on the outside of the nipple when assembling into the rim. This will help the nipple turn freely against the rim during truing, which will prevent binding that can create "false" tension on the spokes. Others have mentioned "nipple grease", which I've never tried but I imagine that works just as well.
- Keep a small amount of boiled linseed oil in an old film canister or small, wide-mouth bottle handy. When assembling the wheel, dip the threaded end of the spoke in in just so there is a very light coating on the threads. This has two benefits: Initially, it acts as a lube which helps the threads easily turn in the nipple (which again, can prevent binding of the metal surfaces). Once the wheel is assembled and trued, and the oil dries, it has the opposite affect and acts like a loctite. This seems to work pretty well to keep the nipple from loosening over time.
Checking Spoke Tension
There's no substitute for a good spoke tension/deflection tool to make sure your tension measures correct for your spoke length etc. However, when you need to quickly gauge a spokes tension relative to the others, give it a pluck or a light tap with your spoke wrench and listen to the pitch of the sound it makes. This really helps tell if all the spokes are ballpark correct when initially bringing a wheel up to tension.
Wheel Lacing Patterns
I've experimented with a few patterns and can say this about them:
Standard 3-cross method: You will almost undoubtedly want to use this pattern, especially for a first wheel build. It's strong, reliable, and it's more forgiving should you make a mistake (you will) and need to re-lace part of the wheel.
Radial: Probably something you want to avoid. Not much advantage besides looking nice and saves a few grams, but it's very important to note a few things, as using this lacing in the wrong application will lead to overly stressing the spokes and premature metal fatigue:
- Never use radial lacing on the drive side of drive wheels. They can't take the twisting force on the hub relative to the rim edge.
- Never use radial lacing on a wheel with disc brakes, for the same reason.
- Never use radial lacing if the wheel will bear weight, such as if a front rack is used.
Half-Radial: This is only for drive wheels, and combines a regular 3-cross pattern on the drive side and a radial lacing on the non-drive side. This is less common, but helps mitigate the naturally unbalanced spoke tension on normal-laced dished wheels, so it may actually make a stronger wheel. Very Important here not to mix up which side is which!
3 leading/3 trailing: This has similar strength and rigidity to 3-cross, but creates a subtle yet attractive pattern. This can be used for drive wheels, but be aware it is a more complex lacing.
Crows Foot: Sort of a mix between a cross-up lacing and a radial lacing, so you get partial advantages and disadvantages of both. The look is nice, but it is a much, much, more complicated pattern to lace, and has the additional factor that you must buy two different sizes of spokes (or four different sizes if it's a drive wheel). This is also limited to wheels & hubs with a multiple of 6 holes.
And finally, I also am a huge fan of the book "The Bicycle Wheel" by Jobst Brandt. It is a simple, well-written and direct technical book, and it's also relatively short.
