For me, the Slow Cooker must be the best piece of kitchen equipment ever. You can cook just about anything in it. Best of all, it is incredibly cheap to run.
For those who are thinking of buying one, I recommend getting one with 3 heat settings--High, Slow and Auto. The 'Auto' setting means that you do not have to manually change a setting from High to Low ( if the recipe states ) as 'Auto' does it all for you.
Also, if you have a freezer, buy the next size Slow Cooker that you think that you will need so that you can bulk cook things like soups and stews and freeze the leftovers. When I started out, I had a Slow Cooker that was big enough for 1-2 portions. I soon realised that a bigger one was more economical.
My favourite cooks are Lamb Shanks, the meat falls off the bone.
Stewing steak with onion that I cook using a bottle of dark beer as 'stock' which I thicken at the end. I then use this as filling for the best steak pies you could ever hope to make.
As for useful cookery books, I bought one years ago that has been the best one as it gives lots of practical tips (which most cook books do not ), as well as recipes It is a cheap paperback called:
Slow Cooking properly explained by Dianne Page.
Published by Paperfronts.
I was about to write good luck, but quite frankly, with a slow cooker, you do not need it.?