Best way to start is to browse through TC manufacturer websites looking at floorplans, camper weights, tank sizes, etc. For a given floorplan, a short bed version will typically have more storage than a long bed version due to wings on the overhang. However, the overall length of the TC will be more limited with a short bed and some sacrifice may be made on the center of gravity.
Be aware that camper weights usually don't include the weight of options which can add up fast. Also add about 500-1000 lb of other stuff you'll be adding (tie downs, chairs, BBQ grill, ax, canned goods, clothes, toiletries, etc.). And don't forget to add the weight of everyone who'll be going along. Total all this up and compare to capacity of the truck.
If the camper floorplans you favor are longer than those available in a short bed version or if you will be exceeding the carrying capacity of your truck then you'll either need to adjust your TC expectations or get a bigger truck (short bed vs long bed, 3/4 ton vs 1 ton, etc).
Once you have an idea of what you like, take a vacation to an area with a number of TC dealers representing the brands you're interested in and start touring. Another option is to find a TC rally in your vicinity to attend.
Happy shopping! I'm sure you'll get plenty more advise here!