Market Research
Identifying a niche is very important, it helps you to make a good decision before you enter the niche.
It'll take me a couple of pages to fully explain to you how I find a niche, so I'll summarize it here.
First of all, use wordtracker, (forget about overture), type in words like review, how to, guide, tips, etc. These words help you find some ideas for information products.
Look for a market with high searches with enough competitiors, then you dig deeper into the market to find a less competitive niche, within the market.
Google the main & secondary keywords, have a look at the top sites & observe who's advertising. Now you can have a quick look at how your competitors or potential partners look like.
Then you decide if that niche is what you wanna give a shot.
Just a summary, hope it helps.
P.S. You can check out my blog, I did a review on a resource which converted me from a wordtracker-hater to a wordtracker-fan.