Good luck, D.! My husband and I started a non-profit which drills water wells in a third world country, so the legal stuff was different, but the process should be the same. The best book I read was the non-profit manegment handbook (check it out at the library or buy on amazon.com). I was told to pray for a love of accounting and I did, and it really worked. And it's a good thing b/c I never realized I would be doing detailed grant management. Grants often require a lot of follow up work and learning different models of accounting is a must. Peachtree accounting software worked for us in the beginning then we had a program designed just for us (we're about a half a million dollar org. now). Subscribe to the foundation center for granting resources and get the grantwriter's handbook, which is published by the foundation center. It is simple and consise. Always have someone profreed your grant to make sure that you never repeat yourself in it or use too many words to say things. Be as simple as humanly possible in your grantwriting. I have been told many times by foundations that our grants are outstanding. It's because I write and my husband butchers what I write. Sometimes I can't stand that, but he cuts out every extra or redundant syllable and the people who read that stuff really appreciate it (I know I'd shoot myself if I had to read a million grant requests!).
Whatever you do, don't re-invent the wheel! Your financial obligation to your donors means that you can't waste money doing that. Pick every brain you can find and hire experiened people. In the long run even the higher salaries will save you money! And the best advice: Pay a decent wage to your employees. Too often non-profits are staffed by underqualified people in order to keep admin costs low. This means high turnover and low quality service. Grow well, grow with a good team.
I assume you've already applied for 501 (c)(3) status if you're writing a grant. If not, form a good board (of wealthy people-- people with connections. there are plenty of good books on board formation) and file for legal non-profit status.
The best of luck to you!