Also I know a lot of regions that are fighting/claiming independence. What convinced the union to come to this decision. What are the Scots woes that drove them to ask for it?
South Sudan passed a similar referendum in 2008. South Sudan has a population of 8 million +, compared to Scotland's population of 5 million +.
Algeria passed a similar referendum in 1962. The current population is about 38 million, I don't have the numbers for the 1962.
Here is a list of independence referendums starting in 1848 with the former US colony Liberia, up to Scotland:
http://www.wikiwand.com/en/Independence_referendum (use the occasion to adopt wikiwand! :)
A portion of the Scottish population wanted independence (about 45%). I'm currently studying in Scotland and I would say the reasons are:
1) Nationalism / Patriotism
2) Feeling of being neglected by London
The election was really split along income level lines with the "poorer" wanting independence (nothing to loose), and the "richer" fearing their economy would only get worse if cut off from London. Poverty reaches third world levels in some areas of Glasgow and Dundee (the two biggest YES cities).