For the beginner the main problem is where to start, and the basic rule is start with what you know! Talk to relatives and draw out a family tree. Your aim is to reach the early 1900s, when most records become publicly available. If you know where your ancestors lived, you may be able to find them a census, available from 1841 to 1901. If you know the exact date of an occurrence, you can call up a certificate of birth, death or marriage, since 1855. Both of these are available on scotlandspeople, the official Government pay-as-you-go site.
Oral tradition, in the form of family stories and patronymics can be used to check and add to the formal sources, and the records available on hebridespeople are an amalgam from these and other sources, drawn together in a lifetime of research by Bill Lawson of Co Leis Thu? Genealogy Service.