What do I need to download to make flash games and how much does it cost? Also will I be able to use a mac to do this?
If you use the opensource Flex 4 SDK, then it would be free; however, if you use the Adobe Flash or Adobe Flashbuilder, then it will cost you lots of $$$ (much more than it is actually worth, I'd say). The tools all work on the Mac. I have the opensource Flex 4 SDK and Adobe Flash CS4 installed on my Mac OS X 10.6 Snow Leopard computer. There were some minor things that needed to be fixed (I had to run chmod a+x
on a few things that Adobe forgot to make executable, and attempting to alter the default install directory -- I originally tried using "/Developer/Applications" instead of the default "/Applications" -- makes the installation completely screw up), but other than that, everything has worked fine on Mac OS X.
As an aside, though, I would strongly recommend you take a look at HTML5 (see A platform game written in HTML5 and HTML5 Canvas Demos) and O3D or WebGL (if you want to make 3D games), if you are looking at developing web-based games. If you want to make games that run on the desktop, then I would suggest you take a look at Blender and Panda3D as alternative platforms for game development.