Photoshop is indeed superb, but very, very complicated when you first try to get to grips with it. It is one of those programs that really requires training to get the best out of.
The helpfiles built into Photoshop are quite thorough but unles you know the processes involved in what it is you are trying to do you probably won't even know what to look for in them.
The Adobe site has a lot of good resource information:
The excellent WebMonkey site has a good introduction to Photoshop [as well as tutorials on pretty much everything else to do with computing]:
Some very impressive guides are on this site:
The processes you want to be looking at are layering and masking. Using layers and masks it is possible to put several images on top of one another [aka layering] and selectively blend elements from each image to create the whole effect you want [masking].
For fine control you can alter the parameters of the 'magic wand' to control your selection a little more precisely.
For very detailed work you can't beat a graphics tablet and PC World are selling some entry level graphics tablets for under £50. A graphics tablet basically gives you an electronic pen on a drawing board and the pen controls the mouse curser onscreen. They are superb for close control of edge selections and general artwork.
A software solution that is truly excellent for edge selections is Corel Knockout. It operates as a plugin to any mainstream image editing software [including Photoshop] and it allows extremely tight control over what you do and do not select from an image. Once your selection is made, you 'knock out' either the selection to keep and transfer it to the image you want to work on as a mask, or you can simlpy 'knock out' the area to remove.
Photoshop is a bit on an enigma to many. I'd agree that it is possibly the single best image editor available in terms of what it is capable of, but its reputation and features outweigh most buyers requirements. Once you get your head around things there'll be no stopping you.