iTunes and IPod?

Sorry I have so many questions. I'll get this all going one of these days so I can help others.

I have an older model Ipod the one with the wheel on it. I think it is 6 gigs. I have a lot of old music all in mp3 format. My car has a 6 cd changer that plays mp3's as well. So it seems to me that staying with the mp3 format is my best bet.

I can chose to add cd's to iTunes in mp3 format which I have done. I opened a account with the iTunes store to down load the music that I want.
So:

Will I be able to download in mp3 format from the apple store?

Should I use a different format that will work on all of these devices?

All the recent items I've gotten from iTunes are in the .m4a format. That is mpeg4. It produces higher quality and smaller file sizes.

You can easily add an mp3 version to iTunes if you're wanting to burn mp3 files to CD to play in your car. Right click the song in question and choose the 'Create mp3 version'.

If that's not the option you have listed for 'Create...', head for iTunes Preferences - General tab - Import Settings and change that to mp3.

If you download songs from the iTMS, they should be DRM free. They won't be MP3 but you can make iTunes convert it for you. Go to iTunes > Preferences > General > Import Settings... > change "Import Using" from "AAC Encoder" to "MP3 Encoder". Once this is done, right click a song and select "Create MP3 Version".