The very basic definition of Spellwork would be the use of magic for an ends. Meaning, using magic for a personal gain, for protection, to help somebody, or to hurt somebody.
There are a varity of ways to do spellwork. Some people use herbs, some use candles, other use tarot. It all depends on what you want to do, and what you think will make it work.
The first thing you have to remember when working a spell is the Harm None rule. The second thing you need to remember is the Three Fold Law. When doing a spell think about if you want what your doing to come back to you. Never do anything that will cause harm to yourself or to somebody else, it's that simple.
Always remember to thank the Goddess and God when you've finshed with a spell. They don't have to give you the magic to make it work, so be thankful. I also thank them when I find out the spell has worked, even if it didn't come out the way I wanted. It's just like thanking your mother for the sweater she gave you for your birthday.
Always think of possible consequences of a spell before doing one. Think of what can come out of it, what can go wrong with it and if in the long run it could cause any harm. If you have any doubt at all, don't do it.
I don't like love spells, and I strongly advise against using them. They take away free will from the person they're cast on (which to me is the worst thing in the world that can be done to somebody), and there is too much that can go wrong with one. You might end up with a stalker; the person may end up hating you; or something worse may happen. Again I say don't do it, or even cosider it.