HTC EVO 4G 2.3 Gingerbread root tutorial:
(Step 1) Power down your phone and take the battery out. Printed on the phone under the battery is a serial number. It is on the bottom line and usually starts with the letters: HT then a series of numbers and letters. Write this code down for you will need it later.
(Step 2) Download superuser from this link: http://www.mediafire.com/?q3ujsx1m4uq1662.
(Step 3) Download the HTC drivers from this link: http://api.viglink.com/api/click?for...13139469417033
(Step 4) Plug your phone to your computer and put the phone in disk drive mode. Now put the superuser .zip on the sdcard and change the mode to charge only.
(Step 5) Put the phone in usb debugging mode. Do this by: home>menu>settings>applications>development>usb debugging.
Also, enable fastboot. Do this by: home>menu>settings>applications>fastboot.
(Step 6) Got to: http://revolutionary.io/ Go down to the downloads section and select either windows or linux. (depending on your machine) Allow the file to download and proceed to the beta key generation.
(Step 7) Select your operating system (windows or linux) and your device and hboot version.
If you are unsure of your hboot version you can check by powering down your phone and holding volume down and the power button (make sure fastboot is turned off before doing this. just make sure to enable it again once you have checked and have the phone powered back up.)
Now enter your serial key (the code you got from under the battery.) select generate key and it will give you a beta key.
Make sure to keep the window open.
(Step 8) Extract the revolutionary.zip and run revolutionary. It should recognize your device and then ask for the beta key. Enter the beta key it gave you, remember it is case sensitive.
(Step 9) Revolutionary will now work its magic. Let it do its thing and DO NOT interrupt it. It may seem like it is frozen but it sometimes just takes a few minutes.
(Step10) After it gets done with all of its operations, revolutionary will ask if you want it to connect to the internet and download the recovery. type the letter "y" and hit enter. It will do it and then reboot.
(Step11) Now you need to flash the superuser .zip. Disable fastboot and and usb debugging and power down the device. Hold volume down and power at the same time until you get the hboot menu. It may check for an image and shouldn't find one. Just let it do its thing. Volume down and select recovery. It will reboot into recover. Now just volume down to install .zip then select choose .zip from sdcard and choose the su 22.214.171.124 efgh signed.zip and select yes. It will flash it. When it is done just reboot.
Congratulations. You are now rooted with superuser and s-off and have full root access.
Thank you, xda. I am grateful for this forum of great and helpful people, without you guys my android life would would be simply mediocre.
Edit: If you need to learn how to flash roms, here is my guide!!: http://forum.xda-developers.com/show....php?t=1230610