That'll work great & all, until you try to put them on an iPod. For some reason iPods organize Audiobooks just straight by the titles of the files so if you have 3 mp3 audiobooks on at the same time you'll have"01 Harry Potter 1 Part 001" followed by "01 Harry Potter 2 Part 001" followed by "01 Twilight Part 001", 02 Harry Potter 1 Part 002", "02 Harry Potter 2 Part 002", "02 Twilight Part 002", etc, etc.
There are some free programs that'll let you make your own .M4B Audiobook files.
If you still want to do the MP3s then I'd recomend ripping with the Bitrate set to ≈32kbps & in Mono. You'll get much smaller files & won't loose anything since it's Spoken.
If you want to go the M4B route, try Xrecode or Chapter & Verse. I'd recomend Xrecode if you're tech-savy, but Chapter & Verse works good & is very easy to use.
For either one you'll want to start by ripping at a higher quality, For Xrecode I use FLAC (Your default MP3 settings should be fine) so that when it's converted there's less loss. I know it sounds wrong since I just told you something else, but you'll delete them after the encode anyways.
Make sure to choose the option to 'Optimize for Voice'. I'd recomend making them into 1 MP3 for each chapter, or at least finding & tagging the ones where a new chapter starts, that way they'll have chapter marks in the file. (So you can easily skip from chapter to chapter).
If you've already made the M4Bs & want to edit the chapters here's a little trick. Use MetaX it's actually a tool for Tagging Videos, but since the M4Bs use the same MP4 container for the chapter info, It'll let you edit it without re-encoding to save (Like if you edit in Chapter & Verse).