Tools for Shingling
Of course, you will need a hammer for driving roofing nails. You don't need a special hammer for roofing, but manufacturers make a heavier headed hammer with a longer flatter claw that you might find useful.
A utility knife is an absolute must for cutting shingles and trimming felt paper. Most come with a retractable blade. Be sure to have a good store of extra blades. Cutting shingles will quickly wear off the sharp edge.
Tin snips for cutting flashing, drip edge and anything else made from sheet metal tend to be more effective than using a hack saw or jig saw. You will variously need a tar brush and putty knife and like as not the ubiquitous screwdriver for occasional odd jobs such as opening tar containers or removing cable wires. At least one extension ladder will be essential for transporting yourself, your tools, and your materials to the roof. For higher pitched roofs, you may also want various appurtenances for scaffolding. These are items you likely do NOT have hanging about your garage. You can rent or buy ladder jacks, which connect to ladders and support 2X10s that you can walk, stand, or sit upon. Ladder hooks can be used to secure a ladder to a roof. A roof-top scaffold made with a pair of roof brackets can also come in handy. And Tarps to protect the landscaping.