Apple → [iPhone] Moving MP3 to Iphone from PC

So I just downloaded a textbook form Flat World Knowledge (first one). I got the book on my Ipad, but I want to put the audio book on my Iphone so I can listen to it in the car. I cannot do it via the cloud (match) itunes says these files are ineligible.

What is the easiest way to get these files onto my phone? There are 93 files to create this book.

Please help I need my audio book if I am going to pass this class.

Does Flat World Knowledge offer re-download?

There are a ton of apps to transfer audio off an idevice. Search for those as the manual route is horrific.

I forgot to mention n the original post....

I downloaded the music to my PC?

Can you burn it to a CD as mp3 and then import into iTunes?

Two choices I've used and been happy with

Free MP3: mp3 only but it does the job

Music D/L: even better and it syncs with Dropbox. I like this one better as it also does m4v/mp4 and with the dollar upgrade it allows unlimited phone storage (up to the memory of the phone).

Two choices, hope this helps.