To complement the compendium of HIMSS tips on his site, I would add a following missive on event coverage.
Gathering information on an event is important for those who can't attend, but also those attending. Keeping up with the buzz and news from an event informs business decisions in addition to serving as fodder for chit chat around the virtual water cooler. No matter how energetic you are, attendees can't be in more than one place at a time. So, finding good sources of information on events is key.
Since HIMSS is the annual health care IT event (even device vendors exhibit here), getting reports is relatively easy. Besides updating this site, I will be checking Mr. HIStalk daily. HIMSS has launched an official show blog, called HIMSS07 Live! that may prove worthwhile. You should also check out the bloggers attending the Meet the Bloggers event (see the list of attendees here) - since they're here, we can hope they'll be sharing their observations and insights during the show. You can also check the bloggers on the Blogroll in the right hand column.
After the event, attendee/bloggers should have wrap-up posts on HIMSS. And later, traditional publications will publish their assessments of the show - be sure to check out mine in MX Magazine. Other sources for information will be photo sites like flickr and blog searches on Technorati and Google (be sure to select "blogs").
Remember, blogging is a two-way street. If you are looking for specific information, want a clairification, or have a request, be sure to leave a comment!