It always takes me forever to make decisions on new gear. Whether it is my next pair of running shoes (because I never seem to be satisfied with the kind I have), a new hydration pack, or a pair of shorts, I always do my homework on the item, because I hate it when I buy something only to find out it just isn't for me - a total waste of money.
The first place I go is other blogs. iRunFar, RunBlogger and Running and Rambling frequently have posts about new shoes, nutrition and gear. These are written by runners who understand the needs of runners, how gear should fit, and are generally unbiased.
If I can't find what I'm looking for there, I might do a Google search for other blogs. These I always approach with a hint of distrust since a blog that I found pretty much randomly might not have the knowledge or background that I would expect from someone doing a gear review - this isn't because of anything about them necessarily - it's just because of my unfamiliarity with them.
Another good resource is reviews on Amazon, Road Runner Sports or another retailer. However, you have no idea about the background of the person writing the review there either. They may have written it before ever opening the package or have no running background at all.
Recently I was introduced to FindtheBest.com - a comparison engine founded by Kevin O'Conner, the former founder of DoubleClick (which is now owned by Google). They launched in 2010 and provide "unbiased, data driven comparisons" for products from bikes to blogs, from shoes to smartphones. It's a great place to go for the stats you're looking for - sole thickness on a pair of Inov 8 Evoskin shoes or the features on a Sole Fitness Treadmill. For the final word, I'll still go to a blog or another subjective expert, but if you just need the specs, FindtheBest.com will work.
How do you find information on your product purchases?