I’m not familiar with Europe 101.  I generally like the Rick Steves guides for reading — you can read one like a regular book.  They’re interesting and there’s a lot of non-guidebook and personal experience in them which makes for interesting reading and can be helpful if you run into the same or a similar situation.  However, they’re a little too much “one man’s opinion” for me to use as my only guide.  I prefer Let’s Go for the guidebook I actually carry with me.

Europe 101 is an easy read for broad european history.  If you don’t know much about history I think it is a good book for giving you footing so that you can better appreciate your travels.  Like I said it is very broad, and much of it is “tour guide history”, based in legends or urban myths or what Rick would like you to believe about history.  If you have any background in history than you many find the historical generalizations and assumptions frustrating, but for a beginner it’s okay.
 
If you are going to read it, read it before your trip don’t bring it along with you.