Spend $500 into one website, maybe a forum! Get a cheap but nice custom skin, domain, forum software, hosting and spend the rest on marketing. If you keep developing it and keep getting new members and posts, you will easily be able to sell it afterwards for $1500!
Brainstorm an idea. (Script, program etc) Hire someone to work on your idea. Use the $500 for the work. Sell the final product for a fraction of the cost. ($75 per license per domain etc) See? You are making money.
I think that was a metaphore for "buy 5 start-up sites from sitepoint.com, redesign and let them age, then sell them for 3-10x each"
Head over to BST section and see if there are any decent training courses/ebooks available with decent reviews. Or join wealthyaffiliate, apparently you can learn a lot from that site.