Before I rooted my phone the fear of the unknown was powerful. What if I wrecked it? Could I ever put it back the way it was when I bought it? Could I BRICK my phone and render it dead, useless? 

I took several months and worked out what applied to my phone...and what did not. As it turned out, rooting the HTC Magic with an SPL of "Hboot 1.33.0004 (SAPP10000)" was ridiculously easy. It's almost designed to be rooted and doing so takes about 20 seconds once you know what you need to do. You can check the SPL on your phone by starting it in Fastboot mode: 

1. Power off
2. Hold down the BACK button
3. While holding down BACK, press the Power / Call end button and release
4. Release the back button 

Your phone should boot up into Fastboot mode showing you lots of system firmware details like the version of the Secondary Program Loader (SPL -> Hboot) and the radio. 

I also learned it is impossible to brick the phone if you don't flash the radio and SPL. You can always get it going again as long as you have a system ROM to flash onto it. 

You can even take a backup of someone else's "Factory Reset" ROM and install it on your phone.......just like the people who made your phone did when they manufactured it. The risk of doing any serious damage is virtually NIL. 

You can also UN-do the rooting of your phone in about 60 seconds....putting your phone back to the way it was when you bought it.....or the way it was when you took your last backup of the 'stock' system prior to rooting it. 

The most valuable tool for both rooting and UN-rooting your phone is a recovery image packed with very useful backup / restore and other system tools. 

A Belgian developer known as "Amon_RA" on XDA has put together (building on the work of others) an almost perfect recovery image in his v1.5.2G for the HTC Magic 32B. Make sure you get the "G" as the "H" is for a Magic 32A and the "R" is for a Magic 32A from Rogers in Canada. Do not use anything but the "G" with an HTC Magic 32B phone. 

Using this recovery you can: 

- backup the current system system
- restore an entire system (all but the sdcard) from a list of previous backups
- partition your sdcard with scripts prompting you as to size and type. 
- repair a damaged partition
- Toggle USB access from a PC on or off while in recovery state: great for getting files on / off your phone if is currently without a functioning system. 
...several other, more esoteric things that are useful from time to time. 

The basic steps for flashing a ROM or restoring from a backup are: 

1. Backup current system. 
2. Wipe system / dalvik cache (and ext partition if you're using APPs to SD). 
3. Go to Partition SDcard and do a "repair sdcard"
4. Then you either Flash a new from from the sdcard OR do a restore. 

Repeat as required. Flash 5 ROMs by lunchtime! What I have NOT covered here is how to get the recovery onto your phone - either temporarily as a kind of 'live' boot - or permanently. My purpose here is to describe how very useful this tool is. 
You can get Amon_RA's recovery here. It's 4MB. (Magnet link for a bittorrent client): 


Here are some screenshots of v1.5.1G. Get 1.5.2G as it fixes a bug with the restore of any backed up ext partitions. 

Main Menu                            

Amon_RA Recovery Main Menu

Wipe Menu

Amon_RA Recovery Wipe Menu

Backup Menu

Amon_RA Recovery Backup Menu
SDcard Partition Menu ('parted')
(Be aware partitioning your sdcard wipes ALL data - so copy all files you want to your PC first.) 

Amon_RA Recovery SDCard Partitioning Menu