Van's does a pretty good job in their manuals. Having said that, Van's is not good about updating their old plans to take advantage of (sometimes clearly) better, simpler ways of doing things. They seem to update plans only if there is a serious mistake. Thus, you're smart to ask questions and search the forums here for whatever part you happen to be fabricating or assembling at the time. Just don't stress out about it too much. Just build, make mistakes, and after fixing them, move on.
Here though are two suggestions to get you started that have a pretty long lineage in the forums:
1. Build the VS before the HS. The VS is much simpler, fewer parts, easier access and helps build your confidence. Those nose ribs on the HS are not for the newbie and the attach angles are not simple either.
2. Related, before cutting the HS attach angles to final size, drill/match drill the 9 holes holes on the vertical face of the angle. This will give you the best chance of getting all the holes drilled with proper edge distance. It took me and many other builders a couple attempts (and probably an extra ordered piece of AA) to get it right.
In general, while there are gotcha's that will be hard to find in advance, Van's produces a great product with good instructions, so you'll be flying before you know it.
Good luck.