What do i need to know to start a website similar to microworkers and mturk??

Hello jennyfree. First of all, you should try to search the net to see if you can find a freeware script about the site you want setup. Sometimes happens that is possible to find a quite good free script for several kind of sites, and this could help a lot to keep your starting budget low. If you're willing to startup a site, probably you have the knowledge you need to setup it. Anyway is not really to much difficult, and for sure you can find some friend that can help you. To minimize the costs, you can get a .info domain (they are really cheap, you can buy it on godaddy for less than US$2 per year), and starting with a free hosting like freehostia (is a reliable free hosting service with a good amount of free bandwith per month). When your business will grow enough, you can transfer to a paid hosting. If you need some more detailed information, feel free to PM me. Have a nice day, see you around.

For any kind of website that deal with database or programming. and as you have told about the website. you must have the programmin as well as system analysis and design capablities to make the architecture of the web application. after that you can convert it into small modules and allot to the programmers so that they can work on them and then test so in short you must know the software engineering concepts and how to complete a project.