There are a few plugins I recommend:
1) Instead of “follow me on twitter”, I like to just have them instantly follow me… So I use twitcapt: http://www.twitcapt.com/ (this is also great if you want to try to go Viral at some point)
2) For auto posting, I use twitter tools: http://alexking.org/projects/wordpress
3) A widget I use to display my latest twits:
http://www.velvet.id.au/twitter-wordpress-sidebar-widget/
Hope that helps
