1) Is your HTC DESIRE sim unlocked? If so then skip to step 2
Go to this thread if you want to sim-unlock your HTC DESIRE
2) Rooting Linux HTC desire unrevoke rooting:
Connect phone to a Linux PC (if you have only windows use a bootable linux cd)
Download unrevoked3 and untar.
From the terminal:
wget http://downloads.unrevoked.com/recovery/3.32/reflash.tar.gz tar zxvf reflash.tar.gz cd reflash chmod +x reflash sudo ./reflash
There is also an app on the market called ‘Quick Boot‘ which you can use to quickly get into recovery from now on.
3) (obsolete, unrevoke3 does it also by default) S-OFF your HTC DESIRE (needs rooting done first) Here is the guide
4) Update your radio (needs rooting done first)
Now you can update the radio click here for details
(Note: there are reports that 32.54.00 may be buggy use the previous one if you have problems with 32.54.00)
32.49.00.32U_5.11.05.27 should be OK
and make sure you have a matching RIL
5) (obsolete, unrevoke3 does it also by default) Recovery image
Unrevoke rooting already installed the clockwork recovery
But if you prefer
the RA-desire GSM recovery
6) Backup (Nandroid).
Before flashing a ROM its safe to take a backup, just in case if something wrong. ClockworkMod Recovery allows you to take a full Nandroid backup of your phone.
Turn off your phone, press volume down and power button, and it'll take you to HBOOT menu.
Go to Recovery by pressing volume down, and press power button to select. Once you're in ClockworkMod Recovery menu, use your trackpad to scroll and select.
Go to backup and restore, select backup, and it'll backup the whole phone which can be later recovered using the recover option.
7) Now you can load your rom of choice...
Here is the Leedroid rom
Good guide for rooting and radio
You can find here the LATEST MIUI
7.1 Enable / Disable AdBlock in your rooted ROM
7.3 Disabling/changing the default BootAnimation and/or Startup Sound
7.4 MIUI stock kernels
7.5 AlarmDroid MIUI.apk
7.6 adb shell problems?
7.7 How to make flashable .zip files
Glossary of Android terms
Have I missed something or got something in the wrong order?