Here are the very specific instructions for voting for Shelley Sekula-Gibbs (widow of local news anchor Sylvan Rodriguez), which walks you through the process of the write-in.
**Note: Straight-ticket R will not vote Sekula-Gibbs in. There is one vote for the special election for the rest of 2006, which contains her name, and one vote for the General Election for 2007 onward, in which her name must be written in.
http://www.writeshelley.com/
This will take you step-by-step through the process. It can be printed out, if need be. Be sure to click the "next" on each page to see all the steps and the ballot write-in demo.
Here's a sample ballot of all:
http://www.harriscountygop.com/site/PageServer?pagename=Elections#2006Ballot
She's also an MD and a current Houston City Council member. She's also very blonde, and very likeable. She's a formidable candidate. If she wins this she will be gold.