http://www.toyota.com/corolla/features.html
http://www.toyota.com/corolla/specs.html
http://www.toyota.com/corolla/options.html
Unfortunately you can only choose up to 4 versions of the 2009 Corolla for comparison on those pages, but that'll show you the differences in MPG, price, and other features and available options for the different 2009 Corolla trim lines.
S manual: 26/35 city/highway MPG
XRS manual: 22/30 city/highway MPG
S auto: 27/35 city/highway MPG
XRS auto: 22/30 city/highway MPG
The S and XRS are the more "sportier" versions of the Corolla. Generally the XRS is more expensive than the S, because it has more standard features (like cruise control, larger wheels, rear spoiler, leather-trimmed shifter). The XRS has lower MPG than the S because the XRS has a higher horsepower engine.