1st u have to have root so go to 4shared.com and search for gingerbreak, download the apk file and install it. Once installed open it and click root(this method actually works unlike z4root). Once it reboots ur good to go. I would reccomend downloading the velocity rom for performance and more battery (also includes overclocking kernel).
Once your done with that it is optional to download launcherpro from the market (recommended) it makes my ally a lot and I mean A LOT SMOOTHER. Here's the battery saver, search root battery calibrator on the market, download and install the one with the red android in the thumbnail. Open it and follow the directions on screen. This should help ALOT