How can I find a mentor or someone to invest in my idea for a business as well as a loan to start one?

First, I hope you have a formal business plan on paper. You can go to the SBA about a loan at http://www.sba.gov, or if you live in a fiar sized city, there may be a local sba. Traditional banks will consider loaning too, but they will expect you to pony up or raise a lot of the cash on your own.

As far as other to invest in your business, I think you may be looking for a venture capitalist or "angel." A venture capital firm or angel investor can provide you with startup monies, but it is usually an investment, not a loan, which means they would own a portion of your business, be able to sell their part, and have their say in how you run it. Have a look at http://www.vfinance.com/

A third option would be a grant....if you are a woman or minority, these are fairly common....just search on Yahoo here for small business grant woman or small business grant <<<insert race here>>>.

Best of luck! My wife and I went through this a few years back, and it can be a real hassle, but work and persistence in searching for start up $$$ can creat great results!