Challenges of virtual reality photography
Getting started in virtual reality photography is easy - all you need is a camera, panorama stitching software such as Hugin, PTAssembler, or a full-featured photo editor such as Photoshop or Paint Shop Pro, and a means of converting your panorama into a format compatible with your VR viewer of choice. While you can find inexpensive or free stitching software, converting to a VR format is going to cost you. Personally, I've used Pano2QTVR (now Pano2VR) with good results, but there are a number of other options out there if you're willing to look for them.
Getting good results, however, will take patience, planning, equipment, software, and skill. Stability is essential for a smooth stitching process, as is proper orientation of the camera (get a sturdy tripod with a bubble level, if at all possible). Very good stitching software (such as PTAssembler, if you're willing to learn it), or one of the numerous all-in-one VR authoring packages out there can make up to some degree for user error, but you don't want to chance ruining a very good panorama on the strength or weakness of your software, do you?
As for the final ingredient, did I forget to mention practice? You'll learn more than you'd think from trying your hand at things, even with imperfect tools. If you're interested in pursuing VR photography further, check out VRMag for examples, tips, and more!