Austin is such a now, wow, happening place in the book world! I find that fellow authors and industry pros are always coming to town, and many of them ask where to stay.
Here's are my personal recommendations:
The Driskill Hotel (downtown; if you're looking for quiet, avoid rooms overlooking 6th Street);
Intercontinental: Stephen F. Austin (downtown);
Four Seasons Hotel: Austin (near warehouse district/lake front);
The Hotel Saint Cecilia (near south);
Mansion at Judge's Hill (beyond downtown but still north central);
Hotel San Jose (near south; if you're looking for quiet, avoid during weekends; but great for diving into the entertainment scene);
Austin Motel (ditto above).
Otherwise, the typical chains apply with the caveat that the Radisson on the lake has an excellent view of the bats (ask for a lake view and/or plan to eat at TGIFridays downstairs during bat season).
Learn about BookPeople, BookWoman, the Texas Book Festival on Oct. 16 and Oct. 17, the Austin SCBWI Regional Conference on Feb. 18 and Feb. 19, the Annual Conference of the Texas Library Association on April 12 to April 15, 2011, and the Writers' League of Texas Agents Conference on June 10 to June 12.