Family history begins at home. There is often a lot more information to be unearthed from within the attics and minds of your own family than you might expect. You just have to look and ask (in a tactful way of course)!
Examples of things you might find are:
Surviving documents
Birth, marriage or death certificates, obituaries, school reports, school leaving certificates, apprenticeship papers, university/college graduation certificates and awards, business papers, military service records, immigration papers, personal diaries, address books, birthday books, letters, postcards, newspaper cuttings, family bibles, memoirs.
Photographs
Families usually have lots of photographs in their possession. It is useful to have an elderly relative identify as many faces as possible on old photographs before there is no one left who is able to do so.
Anecdotal Evidence
Elderly relatives are usually a mine of information on the family and have plenty of anecdotal evidence to share with anyone willing to listen. Photograph albums are a useful introduction - "So what did Great-uncle Jack do in the war?" Of course one must not assume that everything one hears is true - some stories may be embellished over time, but often there is a grain of truth in an anecdote, which can be of use to the family historian. It goes without saying that meetings with elderly relatives in particular must always be handled with a great deal of patience, respect and tact. For example, illegitimacy, which may be broadly accepted today, may be a sensitive subject for someone of an older generation. Remember also that your fascination with family history may well be viewed by other members of the family as an obsession!
Get Organised
Armed with the information gleaned from family sources, you should now work backwards from known facts, using the resources available in your own country.
It is important to be organized and systematic in your approach, whichever method you choose to record your material. Label your sources meticulously - you never know when you might have to refer back to them. Keep a note of which sources you have already looked at, even those that yield nothing, so that you do not duplicate the work. Details that perhaps may seem irrelevant should always be noted - they may turn out to be important later on.
When you eventually uncover an ancestor who was born, married or died in Dundee or Angus, Scotland, you are ready to plan your visit.