OK - so Im all set to do this but just some quick questions. Pls. confirm:
- When I rename the backup- it gives MD5 errors so whats the logic you recommend- "retain existing system name" add a space and then add somethign meansigful. That will not give MD5 errors ??
		
		
	 
I believe I had answered that somewhat in my previous post. Basically, you can use letters, numbers, dashes (-) and periods (.) without issue... As these are what CWM uses by default for the timestamp. I know for a fact that spaces will give md5 errors as the md5 command is likely not wrapping the file name in quotes, so it stops at the first space. Any characters you use beyond the ones I mention are at your own risk. If you rename a backup though and get an MD5 error... don't delete it, just fix the file name... it's most likely fine. If all else fails just name it "1" and see if it still fails md5. If it does, it's bad.
	
		
	
	
		
		
			- After I come back to my present backedup ROM - its CM10.1 Feb 18 build. - say I want to go to CM9 or 10, I can just install from SD card and how do I retain all my apps ??
		
		
	 
Going to CM9 or 10... you're probably going to want to use titanium backup or similar to make a backup of your apps and data. Here's a 
User Guide
	
		
	
	
		
		
			- When you say advanced restore for apps and preferenaces, what specifically do you mean?
		
		
	 
Basically, most everything you're doing in User Space is pretty much stored on the /data partition. In our case, that's /dev/block/mmcblk0p28 (internal memory partition 28). Some things are stored on the sdcard. Others go into /cache. But none of that really matters/gets affected by rom flashing. When you're switching between CM10.1 and anything else, you want to use titanium backup or a similar app. If you're just doing like you're doing now where you're installing stock doing something then switching right back. It's a little faster to just restore /data then continue on. The app backup/restore process in Titanium Backup is a little slower imo.
This is useful to know I guess... Because when you do a factory reset/wipe data what you're doing is just formatting the /data and /cache partitions. This removes anything personal from the phone. /cache is only formatted *just in case* there's something personal lingering there. One of the reason I chuckle when people insist on doing a factory reset, wipe cache, wipe dalvik cache... you've already did the second two in the first step. Like "ATM Machine" 
	
		
	
	
		
		
			- After I update my PRL in stock, I dont another backup ?? - where is updated PRL getting stored?
		
		
	 
No Idea. Personally, I don't really care too much where it's getting stored because I won't ever mess with it. This phone has 30 partitions on it's internal memory as well as the nvram. When you flash a rom You're pretty much only writing to the system, boot, and maybe data partitions. Then wiping the cache partition and dalvik cache (which I believe is just a subdirectory on the /data partition anyway) There's QUITE a few other partitions that do a lot of magic behind the scenes that we don't really need to worry about. Sorry I can't be much more specific than that. Maybe one of the dev types can give you more info *if* you really care.
	
		
	
	
		
		
			- If I'm going across ROMS like CM10 to AOKP- only then I need titanium backup for my apps. correct ?
		
		
	 
Any rom that's not the same base. CM9 to CM10 to CM10.1 to AOKP41 to AOKP 42 to etc etc. Different builds of each are usually subsets of those bases. Take the 
CM10.1 nightlies for example:
cm-10.1-20130418-NIGHTLY-vs920.zip 
cm-10.1-20130417-NIGHTLY-vs920.zip 
cm-10.1-20130416-NIGHTLY-vs920.zip 
or the stable builds:
cm-10.1-20130411-EXPERIMENTAL-vs920-M3.zip 
cm-10.1-20130304-EXPERIMENTAL-vs920-M2.zip 
For aokp:
Nightlies:
aokp_vs920_jb-mr1_build-5.zip
aokp_vs920_jb-mr1_build-6.zip
Stable
aokp_vs920_jb-mr1_milestone-1.zip
Looks like aokp's site just has jb-mr1 which are equivalent to the AOKP42 builds here on the forum that we had before official support.  Either way, from stables to nightlies of the same base you should be fine. If you cross the line on bases... backup everything via app... and wipe data. You'll save a lot of headaches from trying to fix force closes that way.
	
		
	
	
		
		
			When I ADB the push comand you wrote - it says
deamon not running: starting it on port 5038
Daemon started sucesdlly
error: Device not found
I also tried rebooting phone from ADB and it does so but then same..What shd. I do.
Can I just copy the folder to that directory in SD card using winows ??
		
		
	 
Sounds like ADB isn't setup correctly OR you don't have ADB enabled in developer options on the phone. You need to go into the system menu to about phone and tap on the build number like 5 times to enable developer options. Then under developer options enable ADB, and if there's an area that says something like "Root access: Apps" Change that to include adb.
It won't hurt to just copy the folders back and forth in windows. You just won't have that ability while you're in recovery. You could in theory also just pop your SDcard out, put it in your computer and copy back and forth like that as well.
Hopefully that helps.