You are the first person who as actually said that they have seen the crest Tartan.
To start with it may seem a long-drawn out process, but you need to start asking relatives about their background, who was their uncles, aunts, brothers sisters, dates of birth, when they died, etc.,
But please remember that once you start, it is very hard to stop!!
It will get easier as time goes by, i've been working on 2 family histories for the best part of 10 years (Orr Robson).
My own is ORR, and i had aunts, who supplied a lot of information to myself, but also look at census returns, birth death certificates, anything to find your information, even check out the Familysearch.org site, these will all help in your search.
And finally talk to to others, email is a wonderful thing for gathering information.
Last Snippet for anyone who is trying to locate ORR family history..... Wright's Biscuits was owned by Hilda Mary ORR of Cleadon. Factory was based on the River Tyne at Jarrow South Shields, UK. Unfortunately both Mary Hilda are dead now and the company is now in the hands of United Biscuits.
Peter Havelock Orr
Email direct M1dpq_ptr@yahoo.com