Currently, there are a number of good 'live chats' / draft blogs going on (or recently completed) in advance of the draft (in no particular order):
Perfect Game USA live chat;
Project Prospect / DiamondScape Scouting live chat;
Scout.com live chat [A note regarding my Scout.com related comments: for the last 2 years I have been one of two contributors to the Astros prospect section of the FOX Sports Fantasy Baseball / Scout.com top prospects annual. Though I've endeavored to remove any potential bias from my Scout.com related comments, the potential for bias should nevertheless be noted];
Keith Law (ESPN) chat; and
Baseball America draft blog.
For Astros' specific draft chat and information check out:
The Crawfish Boxes; and
The 2011 Draft thread at the Bus Ride Discussion Forum (SpikesNStars) [Again, in the spirit of full disclosure, I am a moderator at the Bus Ride].
And finally (for the moment anyway), a site that I highly recommend: 'Cats Corner.
For those of you who are not familiar with 'Cats Corner, it is the official blog site of the Tri-City ValleyCats, and (in my opinion) provides the most in-depth Astros prospect information of any of the Astros affiliates. Kevin Whitaker is working with the club again this season, and will be part of the ValleyCat team hosting a live blog of days one and two of the draft. Be sure and drop in and give them a read.
Edited to add: somehow in the midst of all the information above, I inexplicably failed to mention that you can follow along with the draft through MLB.com's Draft Central.