There are many types of brass, but for my projects I mostly use:
half-hard sheets and tubes - It is low lead and easily formable (bendable). If you want high polish, try to get sheets with protective film that you leave on till the last possible moment. You can put tape on the sheets to minimize scratches. It is also known as yellow brass or cartridge brass.
rods, hex, square bar - It machines very nicely. It has 3% lead so I wash my hands after working with it and clean up all the residue.
Brass anneals (becomes less stiff) with heat but cannot be heat hardened. It hardens by bending or stretching it. In the home shop you cannot really harden brass. When you bend it too tightly or too many times it will crack from hardening stress. Half hard brass is a nice balance between stiffness and workability.
For this project, used .032 inch thick (20 gauge) sheets and strips from K&S bought from the local hobby store, or eBay
For larger projects and to stock up, I use OnlineMetals.com, they have a nice sample pack here
Compound Aviation Snips - There are straight, right and left cutting. A nice pair is $16
Rulers and calipers - I love my $2 plastic calipers
Step drills - good for clean hole drilled in thin sheets
Twist drills - not as good a step drills on thin metal, but can get more exact hole sizes
Center punch - lightly punch centers before drilling so the drill doesn't wander
Files - rounding corners, removing small amounts of material
- clean way of making softly rounded edges
Fine-point magic marker
Tinsmith or ball peen hammer - not a woodworking hammer please
Cereal box cardboard - for templates and mockups.
Drill press or electric drill
Vise with soft jaws - I made soft jaws from HDPE plastic scrap, (like plastic cutting board material)
Propane torch with cylinder
Stay-Brite silver solder with flux - 1/2oz package will last a long time. No cadmium or lead or other undesirables
C-Clamps or vise to hold parts in place
Cleaning and polishing
Ultra fine sandpaper
Bar Keepers Friend cleaner and polish