Good suggestions so far on this thread...I have learned a lot about Scottish folk from listening to Dick Gaughin and The Corries, who mostly do traditional songs. Dougie MacLean is wonderful as well...he does mostly his own original stuff, but he seems to already be deeply ingrained in the Scots culture (his 'Caledonia' is sort of an unofficial national anthem for Scotland.

Two bands I've not seen mentioned yet: The Tannahill Weavers (named I assume after Scotlands other famous poet, Robert Tannahill)and The Old Blind Dogs a relatively new bunch who are really fun!

To give you a taste of the LOCAL folk scene in Scotland itself, you can try this link:

AlbaMusic

or you can check in with Dougie MacLean's Taybank Radio

I don't know where you are located, but you mentioned having trouble finding Scottish folk songs on CD. Most Border's Bookstores here in the US carry the GreenLinnet label, which has CD's from many of the artists on this thread.

Finally, I expect that some of our Scottish 'Catters themselves will be along shortly to put their tuppence in...I had fun attending the last two Scottish Mudcat gatherings by mobile phone across the Atlantic, and those guys and gals seem to really know their stuff...they should do, they attend live folk sessions weekly!!