It really depends on what tools you use. First of all your tripod head will be the most important, you need to be able to rotate your lens where the diafragm is (many lenses have a gold ring at that point). If you take your shots rotating a preset number of degrees every time, it will be easy for your software to join them for you. I used to work creating those VR tours and I used Stitcher 4 to create them. It's made by RealViz. It's pricey but they have a trial version on their website. I'm sure you can find other software, probably some free that does the job but this is what I have experience with. This is their website: http://www.realviz.com/products/st/index.php
