Guiness:
I like Trek. There are lots of good names out there, but I figure Trek got to be so successful for a reason. Also, you have different brands available in the US than we do here in BC. Trek is well-represented here.
Trek has a good web site, you can do a fair bit of research right there.
www.trekbikes.com. I would start in the road section of the site, and see what the differences are between the ranges. MSRP is shown. There are also bike review sites, but you need to sort through the fanatical comments to decide which ones apply to you.
Shimano is pretty much the standard for components. Dura Ace group for the real racers, Ultegra is a step right below that, and then they go down from there, through 105, etc.
There are a wide variety of styles/riding positions available. The tri athletes tend to use frames with a dropped top tube (towards the rear), and those are available in several different lines, while classic road bikes have a top tube parallel to the road. Several companies are now putting upright bars on high-end frames, but I don't really see the point, myself. Trek calls theirs the Pilot. Having said that, I changed to a different stem (rise and reach) and brought the bars in closer so that I am not dropped quite as much (see the photos). If you want, you can add suspension (rear triangle, seat post, etc) but that adds weight and reduces pedaling efficiency. Just buy good riding shorts.
One of the big choices to make will be frame material. Chrome moly tube is classic. Aluminum, titanium, carbon, or combinations of the above are all available. I like the idea of a carbon frame without lugs (joins) since I think it is stiffer. You want lots of stiffness in the main triangle (so that you aren't expending energy flexing the frame each pedal stroke) but some compliance in the rear stays really helps with the comfort factor. A full carbon frame like this lets the designer work towards both objectives. All it costs is money, but there are so many variations available that it is really about how much you want to spend.
My last suggestion is to find a good bike shop. A reasonable bike probably doesn't come from a discount chain store. Also, a cheap bike that fits will perform better than an expensive bike that doesn't fit, as a rule of thumb. A good bike shop will fit you, and work with you to make sure your riding position is optimized. That is worth the premium over the mail order houses, IMO.
Good luck.
Jeff