Take a look at these, they cover alot of the basics for beginners.
http://www.simmerspaintshop.com/foru...nder-tool.html
http://www.simmerspaintshop.com/foru...ins-voids.html
http://www.simmerspaintshop.com/foru...ts-il2-fb.html
Not sure which program you are using, but there are many tutorials submitted by staff and members to cover lots of techniques with each of the major programs.
And of course, if you get stuck just ask!