Economic Research Institute Free access to current and older 990s is available, along with a variety of search features similar to those formerly provided for free by Guidestar.
GuideStar This site gives you access to the 990 tax forms of private foundations. Here you will check out who they gave to, how much, trustees, and financial information about the foundation.
Nonprofit Guides Has a sample letter of inquiry, proposal, proposal cover letter, budget, and other items that may be of use to you.
InnoNet's Non-profit Toolbox Innonet is a nonprofit dedicated to assisting the development of proposals online in a secure environment. Great examples and templates.
Fund-Raising Has Fundraising ideas and information Links.