Yay for a new garden! If it's summer for you, you might have luck killing the weeds by laying something heavy and dark (like a rug) over them until spring. That's something a friend of mine does (she has a house with a big lawn, and her goal is to eventually replace all the lawn with garden, so she does this every year).
You might not need to till the land--people are saying now that it destroys soil structure--but you might want to get some humus or compost and mix it with the dirt you've got.
For tools, I've used a shovel and a trowel, and that's about it. For plants, I second Honeysuckle's comment on what do you buy? If you're looking to grow vegetables, things like shallots, tomatoes, and herbs are fairly expensive in the store and easy to grow. Lettuce is also easy to grow and good to have around if you're a salad person. Raspberries and strawberries are good too, but will spread like the dickens. If flowers, what kinds do you like? Would you want a garden for cutting flowers to bring inside or flowers to stay outside and bloom?