If you are going with third edition/OGL (the 2000 to 2008 version of D&D, and the foundation of Pathfinder RPG, True 20, Mutants & Masterminds, d20 Modern, Arcana Evolved, Iron Hereoes, etc.), then...
...if you haven't already, I'd start with
WotC's archived
OGL information
here.
The most relevant pages would probably be the
Open Gaming Definitions FAQ, the
OGL FAQ, and the
Software FAQ. Also the
OGL itself it around 1 page-ish in length, so it's not too terrible to actually dig in and read.
Oh, but any references to the "d20 System Trademark License" are old and no longer relevant. That was an additional license for using the d20 logo to indicate compatibility. But it's gone now, even if some references to it remain in the FAQ's above.
I don't know if anyone will take you up on your offer given how loathe people are to offer pseudo-legal advice over the internet. But much of the basics are pretty straightforward (as far as contract licenses go, that is).
Your best bet might be to ask specific questions. I'm sure most any have come up in the past and been argued to death years ago, so people might be willing to give "the consensus seems to be" sort of answers.

You can probably throw specific questions out there without necessarily spilling the beans on your project. Besides, most people who would have wanted to develop
3e software and websites probably already have (although maybe Paizo's Pathfinder will breathe some life into the edition and spark new developments).
If you are working on 4e material (D&D 2008+), then...
... good luck. The rules are in the
GSL, and are far more strict than the
OGL. Plus with
WotC getting into the digital arena themselves, they are being far more protective of their content.
The other option for
4e material would be the "copyright" route (referencing the court case or three that supports the idea that game mechanics aren't copyrightable, just the "implementations" of them). But very few will go on record with advice on exactly how to do that beyond "talk to a very good lawyer".