I went to a scrapbooking class that was run locally, but to be honest all we did was do our own thing. We started with a cheap scrapbook from a stationers, added backing papers, our photos, journalling and punched shapes, tickets or embellishments as we went.
Best thing would be to look on some websites to get ideas of how other people have done theirs. You can collage photos together or just use one big one, use the pages individually or as a double-page spread. I printed my photos at home, but if you use photos with chemical paper you need acid and lignin-free papers and embellishments to avoid damage being made to the photos. Try it and see how you get on. You can buy loads of things suitable for scrapbooking, you don't have to do 12x12 books as there are 8x8 blanks available and you can print out papers from home and cut them to 8x8 from A4. Lots of downloads online for starting out. Try this site as it is all organised by type of downloads.
http://www.freecraftstuff.co.uk/