[EVO 4G Android Development] Faust*:
Well welcome first I know this all can be a little confusing but I find if you take a step back and a big breather it can help a lot especially if you just finished rooting now. Ill try to answer you questions to the best of my ability, I'm new myself but have done this a lot already flashing different roms, rooting/unrooting.

Fiirst off this idiot proof quide is still toasts method just explained in a very detailed manner to help everyone, even people who consider themselves advanced in whatever way can easily get caught up in all the terminology and files available.

Now technically one could say there are 3 rooting methods some more permanent/involved than others.

Unrevoked is barely by itself root. It uses an exploit to give you temporary root access, but it only lasts until you restart your phone. This guide uses unrevoked to give you temp root access so you can download titanium backup to backup your apps before you start toasts method then restore them when you are done. But there are a lot of people out there who use unrevoked with nothing else just so they can run somethine like the free wifi tethering app without getting their hands too dirty or mess up their new phone.

The second type would be partial/half root which is everything up to step 35a right before section V. Think of partial root as a sort of permanent root but with a lot more you can do than you could with just unrevoked. For starters you can restart your phone all you want and you will still be rooted. And secondly if you follow the steps for partial root correctly you now have clockwork mod recovery and can flash any custom rom you want.

Last you have full root with nand access. If you follow to the end of this or part two of toasts guide then you have replaced clockwork recovery with amon ra's recovery. (clockwork gives you green menus while in recovery, ra is yellow). Have nand unlocked means you have full read/write capabilities within adroid so now you can use a file manage to view everything above just your sd card. You can also make full nand flashes which are backups of everything (not just your apps like titanium backup does), which is handy if you want to switch between different roms to try them out. You can say, flash your current fresh rom, switch to damage control then if you dont like it easily go back to fresh with your nand backup.

Now as for your other questions, once you have partial or full root with nand unlocked you DO NOT have to flash new roms through usb and adb. Just move the rom you want to your SD card, power down the phone, hold the down volume button and power back on. It will try to look for the PC36IMG.zips but if you rename them like the guide tells you two in a few seconds you will at the screen with androids on skateboards. from there go down to recovery, hit the power button to select and it will take you to either clockwork or amon ra's recovery depending on which root you went with. From there you just choose to search for a zip on the sd card then use the volume buttons to navigate to the rom and select it with the power button.

As for rom manager I have never used that so I can't tell you much about it. I myself always stick with a stock rom so I don't change roms much unless and update is out.

And last but not least yes, you should always avoid the OTA updates even if you are using a stock rom. Wait for the developer of your rom or another to incorporate them into their creations or risk losing your root or potentially worse.

I hope I was of help to you in some way =]