As you may remember, I'm still searching for the ultimate laptop. I've been scouring reviews web sites (e.g., NotebookReview.com) reading about several possible options (Sony Vaio Z series looks amazing, and so does the new Samsung Q series). I ran across 2 documents (put out by Microsoft, no less) that advise on getting a laptop that's right for you.
The first is called Laptop Selector, outlining all the features and attributes laptops have nowadays, and which are important in making your decision. The second is simply titled "10 questions to ask when buying a computer", detailing the purchasing process and the questions you should ask the seller before committing to a deal.
Bear in mind that there might be a Microsoft angle in the first document (i.e., stirring you to buy a Windows supporting laptop), but it does contain quite a good review of the laptop-purchasing decision-making process.
I've uploaded both documents to my SkyDrive to ensure they remain available (don't know what a SkyDrive is? Read this).