Below I list some of the most useful websites I have found in my quest for Scottish family data.
This is a truly phenomenal website -- the official government source of genealogical data in Scotland. Containing almost 50 million entries, this site covers all Births, Marriages, and Deaths since 1855 in Scotland. There are a few limitations on what data is available to protect living people. For example, Marriage data is only available up until 1933.
In addition, Old Parish Register (OPR) data is available from 1854 back as far as 1538. Scottish Census details are also on the site.
There is a charge for using the service. Searching is free; search results costs 1 credit; viewing a certificate is 5 credits. [5 credits = £1 ($1.50)]
Several libraries throughout Scotland offer vouchers for ScotlandsPeople at 20% discount. These must be bought direct from the library.
The Mitchell Library, Glasgow
The main library in Glasgow, this has an excellent family history section located on the third floor. Records include Census returs, Old Parish Registers, Poor Relief records, Burial records. All information is free