It can be a good way to go. It might also be cheaper just to get individual tickets from the various national railroads. It depends on how and where you travel. When you get a Eurail pass, tou still have to make reservations on most of the fast trains, international trains and night trains and pay a supplement for each train. The pass does not generally require an additional supplement for the slower regional trains that make a lot of stops.
See:
http://www.eurail.com/eurail-reservation… ,
http://www.eurail.com/eurail-reservation… ,
http://www.eurail.com/eurail-reservation… .
There are often discounts for early purchase of individual tickets on these same trains. For example, right now you can get 15% to 60% off on Alta Velocità trains here in Italy -
http://www.trenitalia.com/cms/v/index.js… . However, it is extra work to deal with all the individual railroads and you need a fixed schedule to really take advantage of the discounts.
There's a lot more information here:
http://www.seat61.com/ than there is room for in this answer.
Train travel is a great way to see Europe. I've been going out and exploring most weekends and holidays for about ten years now and use the trains most of the time.