In case you haven't found it yet, http://www.simonov.net
is an excellent source of information for the SKS.
The type of barrel should be readily visible without any disassembly. You just have to look under the rear sight block. If the barrel has a "collar" where it meets the receiver, it's a threaded barrel. If it just goes straight into the receiver (and has a gap between the barrel and underside of the rear sight block), then it's pinned. Here's a good page that describes it: http://www.simonov.net/uberthread.htm
Again, welcome to the forums. Make sure you come back and post regularly. We could use more SKS discussions around here.