There are two categories I'd look into: technical and market (sorry if this is overly basic- it's what I did though and it seemed to work).
It seems you are asking about technical stuff-- which often limits what you can do in a certain market.
To learn about technical issues I see three ways:
1. The Research Nerd way: all your ordinances etc. should be online. Or at least downtown or at the county seat! Read them. It takes a while, leaves you with more questions than answers sometimes, but it is very valuable to see what's written down. If there is a dispute, this is what it often comes down to. Sometimes even the officials in the planning office will say something contradicting what's written down.
Plus know your state laws! For example, in NC you can divide tracts without having to create a subdivision as long as the end products are larger than 10 acres.
2. The Good Ole' Boy way: Talk to your local good quality surveyors, excavators, well guys etc. They know the soft edges of what can and can't be done, and can clear up some questions that reading the ordinances bring up. Realize that they have a slight bias to do things, rather than not. In my case, my surveyor called planning and got something through I might not have been able to. He had a good reputation with the decision maker. Always listen to your good contractors and subs! Of course not everything they say is golden-- but they have gems that will save or make you $$ on this deal or the next. Visit successful and failed projects and talk to the neighbors. (of course this is good for knowing your market too)
Talking to your land/real estate atty straddles the good ole boy way and the next way.
3. The Upstanding Citizen way: Talk to your attorney. Get the dope from him/her. Ask all kinds of questions, yes like Ryan said even ones that sound crazy at first! Get recommendations for good surveyor etc.--- ie the ones with the fewest lawsuits on their tails.
Call planning, ask general questions that may apply to your project (not mentioning a specific piece of land). I'd tread lightly on this one until you have a good rep. and are one of the good ole' boys yourself!
For the market I'll be brief: Know it well. On the ground, not just by computer. Is there a need/want that you can fill that other places can't/won't? Women make most housing decisions (probably less so for lots), what do they want? Paint the picture for them.