I wouldnt be without mine, its always in use. The lid does just sit there and when it starts to bubble the lid bobbles up and down, it makes no difference to the cooking.
You will need to practice with it, mine is a big family sized one and nothing ever takes as long as the recipes say, although mine has 2 heat settings and then a keep warm setting, so if you find your meal is cooked before you are ready, it just stays warm without overcooking.
You dont need to spend a fortune on these, mine cost about 17.00 from Argos, no brand name, and as I said, in use most days.
You can get some good books on ebay or Amazon.