I have a confession to make: I worked in marketing, so asking for personal information was a huge part of my design challenge and I strive to relieve the stress of coming on to yet another form by limiting the number of fields (if possible), reducing the footprint of the form itself and providing a short description of benefits of filling out the form and getting the information. Please try to keep in mind that the best practices for reg form design is limited by a real-life technology available to this particular designer.
In the last year or so, I've made a conscious effort to streamline the reg form design and offer relevant content and links to related content whenever possible. The result: increase in the pages viewed per visitor as well as higher registration numbers (this may not seem important, but, in the end, that is how many B2B companies stay in business - driving leads for sales, selling the product and so on).