Can highly recommend that guide, it's worked for me. There's also a very good book you can buy on Amazon called
Cat versus cat, which contains some good advice although most of it similar to this guide. My advice would be not to get too despondent if things aren't good between the two cats straight away. I've got three, and had to introduce Bertie and Bella first, and then Minnie to both of them later. It took about a month for things to settle down between Bert and Bella, and Minnie took around nine months to settle in. I'm sure nine months is a lot longer than the average cat (especially as Minnie was semi-feral and blind, which made things harder, and was also 7 years old whereas B and B were both under a year old when they met), but it proves that cats can start to get along after a period of time even if things aren't good initially. Good luck!