Congrats! You're launching a talent marketplace. You've got the platform, but you still need a great logo.
If you've got a healthy sized budget, we highly recommend working with an agency. If things are a bit tighter, there is 99designs. You can get a logo designed inexpensively, with multiple options to choose from.
Looking to try your hand at logo design yourself? http://tailorbrands.com allows you to create a logo in under 10 minutes.
Pro tip: If you don't want to pay, you can create one and just take a screenshot of the logo and add transparency to it.
If you have resources you should try and invest in a brand guide.
"What is a brand guide?"
A brand style guide is a document that codifies how an organization presents itself to the world. Put another way, it’s a reference tool that helps maintain consistency by demonstrating what a brand looks, feels and sounds like. It’s so powerful that some people even call it a brand bible, but don’t let that intimidate you. Those are just different names for the same document. It includes brand colors, fonts, logos, and so forth.