Accommodation
Hostels
There are plenty of hostels in the tourist centres of Scotland, such as Edinburgh and Inverness, and booking is not usually essential outside the summer peak. Many of these hostels are able to provide pretty good deals to people who want to stay for a few weeks at a time, and Edinburgh in particular is a popular place to do this. MacBackpackers in particular run a chain of reasonably good hostels in various tourist towns, and even run a tour bus which connects them.
Outside these centres there is the usual selection of hostels run by the SYHA, which is the local Hostelling International affiliate. There are also a fair number of out-of-the-way independently-run establishments. Smaller hostels which provide fairly basic facilities are often called bunkhouses in Scotland. These sound basic, but are often on a par with hostels in many other countries, and are ideal if you are touring around the Highlands. Actual listings of hostels are provided in the section for the relevant area
Hotels
Scottish cities have the same range of chain hotels as the rest of the UK. Operators such as Premier Travel Inn provide much the same service as they do everywhere else. The general standard of hotels however can be pretty awful, particularly with regard to cleanliness. If you're going to splash out, do it elsewhere.