I almost always invest via mutual funds. (I'm either in equities or cash, I ignore other instruments - not justifying it, just noting that I don't follow the other stuff at all.)
To evaluate funds, like when joining a new 401k, I typically use a combination of
Charles Schwab [reports](http://www.schwab.com/Schwab N O W/S N Library/S N Lib122/S N122main Mini Home/0,4525,504,00.html?Orig=phome&pos=topnav&ebmk=phomeAcquisition&dest=mf) which gives 10-year returns, plus quartile-within-category rating for each of the past few years.
I tend to ignore "captive" funds, those run by banks, insurance companies, Am Ex, etc.
I also typically ignore funds that have been in operation less than 10 years - and they should have had the current main manager for that long.