Have you checked out the spells section? In regards to that, it's easier to say anything that promises to change your body won't work (with the exception of diet spells that are based on keeping the dieter motivated), things like flying, levitation, control of the elements, spells won't work. It's generally accepted that these things are only possible in the astral plane, so you may want to look into that. Beyond that, just about anything else will. If I've forgotten something, someone please add.
In addition to what bttrfly has said - the use of common sense can go a long way. If it seems unreasonable or has been featured in the latest Hollywood blockbuster chances are it won't work. (e.g. time travel & teleportation).
I have a list of things magick won't do on my profile if you'd wish to read it. Apart from that though just keep in mind spells won't achieve everything. There are limitations as is with everything in the universe.