avi -> dvd
yes, several, but dvd creation needs some knowledge. It's easy to convert the avi to correct format for dvd, but creating menus for dvd is not yet very simple. Also you need to think the conversion also (interlaced video should be kept interlaced to preserve maximum information, even non-interlaced video will be written interlaced on the dvd), so do some googling about dvd and interlacing.
Easy gui-programs for format conversion:
tmpgenc (30 day free trial, does not count as free though)
For dvd creation:
simple gui frontends to dvdauthor: