There are many free programs for creating and editing graphics and for manipulating video files. Before you spend a bunch of money on the excellent programs from Adobe (Photoshop for graphics and Premiere for video), Google "free graphics program" and "free movie program" and do a few trials. If you are running Windows XP+, you have the not-so-terrible Microsoft Movie Maker program already on your computer. You can use that to edit your movies and export them into a suitable web format.
As someone who enjoys making life difficult for myself (
), I have learned to use the robust Graphic Image Manipulation Program (the GIMP), which is very nearly a complete Photoshop replacement program and costs nothing.
Similarly, I use a program called "SUPER ©" to encode my video files for the web. It, too, is free, but you'll want to use something like Movie Maker to edit your videos and add transitions and titles before you encode them.
That being said ... once you have your graphics, it's not much trouble to include them in a web page. As far as posting video, however, there are lots of options that it would be a good idea to learn about before you dump your video content online.
A very simple way to get your video online is to create the video, edit it and then upload it to a YouTube account (if it is not a private video ... which should be kept offline, anyway). Then, YouTube gives you a little code you can put into your web page, and the video will show up. The beauty of this is two-fold: (1) YouTube handles the encoding and the player and (2) the video is stored on and served from YouTube's servers, so you don't use up all of your hosting storage space or alotted bandwidth! Sweet!
These are just a few ideas for getting started. Have fun!