Reading everything on the wiki will help, and selecting file/new template/example and having a browse through the examples should help.
It can be quite time-consuming making a good tutorial (I think the Ghost Shooter one took a couple of days). I'd really appreciate if anyone else came up with tutorials - I'm stretched for time as it is, and time spent writing tutorials (although useful) is time spent not coding Construct. Still, eventually, I'll get round to writing some more, if noone else does.