Help with map editor

I kinda needed some help with editing SRB2 maps and making my own, you see I got • Doom Builder 1.67 and need some help with how I should go about using it. Or if I don't have the right thing, if I don't maybe you could tell me what I should use. Can someone help me?

There is a tutorial for Doom Builder here http://www.sepwich.com/ssntails/mb/viewtopic.php?t=1280

It's pretty imformative and will get you going with making maps.