Bolt Threads

Hello:
I am new to Solid Works and I have being enjoying the softwarealot. I have an issue. I am not able to find this particular boltin the library and I would like to create one. The problem that Iam having is creating the "thread" feature that a bolt have. I havelooked at a few tutorials using the Helix/spiral feature but , butthey were not clear. on the explanation.
Does anyone know of a tutorial that show this processstep-by-step.
thanks in advanceSolidworksSurfacing