Having a good idea but dont have enough money to invest
Bootstrap it... break the idea down to its core, so that you can build it as effectively as possible.
Once you have an idea of how much capital is required multiply it by 2x. That is how much money you will have to raise.
Then: 1. Use your own cash... cut down your expenses, eat top ramen, and invest your own money 2. Ask family and friends to invest.
Once you have gotten as far as you can get, then look for outside investment. Investors are very unlikely to put their money behind an idea if you have not. An idea is worthless, its the drive and passion to build a business that most investors look for (to exploit) and can be profitable for them.
The reason you want to aslo avoid investors is the more they put up, and the earlier the less you will end up wiht.
Try to minimize your development costs as much as possible. Use studen labor (interns), offshore, etc.
Depending on the idea, it can be built with a couple of people usually, to the point where it will have enough traction to raise investments or use profits to grow .
Best of luck
There are a few programs I know about that might be of interest to you:
Both are good places to post your idea and if of any interest to angel or any other type of investors, your idea could get funded. Good luck.