From a design / video perspective, these are pretty much the basics ..
Adobe Photoshop for Bitmap images (Raster)
Coreldraw for Vector Images (Vector) although you can use adobe illustrator
Flash for animated Vectors
Notepad / Dreamweaver for HTML/PHP
Fonts from
http://www.1001fonts.com
Font viewer from
http://www.boilsoft.net
Gif animator for animating banners etc, although you could use Image Ready which comes with photoshop cs
Sony Vegas Video or Adobe Premiere for the video editing
Shit loads of codecs from
http://www.free-codecs.com/
Any decent ftp package
Nice to have ..
3d studio max from
http://www.discreet.com and you will need time to learn this as well, its a huge bastard and very flexible.
Cleaner XL also from
http://www.discreet.com for video as well as Sorenson Squeeze and/or Canopus Procoder