How do I remove MacKeeper and other adware on my mac? Please help

I Have recently joined the Mac community, my wife, thinking that a MacKeeper popup was a system program and installed it. Shortly thereafter our browsers began getting hijacked. Since then we have uninstalled MacKeeper, however I think it is still running in the background. Our browser is constantly redirecting to other sites. I found a post from a "linc Davis" that suggested running a command line Unix script to discover what was running in the background, and sure enough, MacKeeper is still there. if anyone out there can help me I would highly appreciate it. I'm at a loss, I use my Mac to view highly confidential info, and cannot even risk using it until I get this fixed. Thank you so much.