I will try to answer both of your requests:
1) You can add a link to webkit-sharp.dll by right-clicking on the "links" in the "solutions" area:

Then click "Edit Links":

Then select the ".NET Assembly" tab. Go to find "webkit-sharp.dll" and your set as far as the links go. In your code, of course, you'll need something like:
using webkit-sharp
2) . , , , MonoDevelop winforms, GUI-, afaik, winforms, MonoDevelop. MonoDevelop GTK # . ( , , .)
CHEERS!