I attended the WAS V7 Administration course (www-304.ibm.com/jct03001c/services/learn...) It was a remote classroom sertup, which was pretty good, but not perfect. It was definately better than learning on your own, but the instructor was in Denver, CO and I was in Columbus, OH. The price is $3125 for a 5 day course. In retrospect, it was definately worth the cost.
The course was populated with a mix of people using WebSphere on Linux, AIX, and Distributed systems. The benefit was that even if you did something correctly, odds were high that someone else may not have. When this happened, most people jumped in and tried to help out and we all learned a good amount of how to troubleshoot issues.
This past year, I attended IMPACT 2010 in Las Vegas. While it's a conference, the amount which you can learn is fantastic. I highly recommend trying to attend next year's IMPACT conference in April (again in Las Vegas.)
As Susan called out, there's nothing better than hands on experience, even if you do it on your own.
I'll also agree with Susan that I (personally) don't find certifications incredibly valuable in my job. ALthough, if you're a consultant, they do indicated that you're well rounded in all aspects of WebSphere (and let me tell you, if you pass the test, you do understand most of the core concepts!)
I've taken one of the tests for WAS 7 at IMPACT (it was free with my paid attendance.) It definately was not easy. I found that the areas which I knew, were those I dealt with first hand. Those I didn't know were because I didn't work with the suite in that specific capacity.
As Susan called out, there are places where you can pay and take a pre-test, too. They are pretty reasonable, all things considered. But, with all things IBM, nothing is free ;-)
Is there anything specific you're looking to learn?