Can someone please help, I transfer files to DVD and CD but they are in AVI how can I convert them please

You need a conversion application. Here's a free one I've heard is good but I have not used it myself. http://www.tmpgenc.com/ I use ULead Media Studio, but I also paid through the nose for it. It IS worth every cent.

You might want to look here;
http://www.afterdawn.com/software/
You can find free software ,a ton of info and some forums for this stuff.

Many newer DVD players can play DivX and XviD AVIs directly so you can just copy the files to the CD/DVD.

I've had a lot of success with a program package I got from a link on doom9. It is called DIKO free 0.73 and is excellent in terms of the quality. It is also all legitimate free software. It does take a long time to convert, but creates DVD videos at about 2-3Gb per hour which scan through (forwards and backwards) and have fixed 5 minute chapter points. It is useful to have a copy of VOBedit and IFOedit if you are joining several smaller clips, as otherwise it will just play the first one on a standalone unless you catch the track forward button at the right moment. Downsides are the time to convert (usually about 2-3 hours per Gb of finished video) and the fact that the conversion process needs about 15-20Gb of space to write to. Don't worry though as you can delete all of the stuff it creates except the DVD Video files which you want to burn!

believe it or not
nero has converted about 95% of my avi's without error
xilisoft another goode
then there's mainconcept
render times may vary more memory faster render
don't use nero to author takes to long
movies and congressional sessions I have converted about 600
some I made

WTF is it with people digging up ancient threads?!

Xilisoft AVI to DVD Converter can help you to convert avi to dvd.