Here's a guide for new animators that want to know which spritesheets to use:
For a big overall spritesheet, I recommend the MadCom_Ultimate_Spritesheet from Neztech (Look for a blog post on Newgrounds for a sprite page it should have the link to that)
For the new design sprites such as the 9.5 sheet or dissenter, etc. I recommend getting the Dissenter Spritesheet from the Resources Tab on Madnessarchive.com
Also, if you want to download flash, you can download Flash here. (Practice caution while downloading files on the internet also.) Make sure to download Flash 8 or Flash CS3 or CS4 or CS5 or CS5.5 or CS6 as those are the most compatible versions. I recommend CS5.5 for easy installation, it is very easy and comes with a S/N.