Hi there, welcome to the world of android LOL! Here's the steps u need to do (found it via Google) : http://www.addictivetips.com/mobile/how-to...android-backup/

For SGS+ to reboot into the recovery mode, switch off your phone, press volume up + power button until the samsung logo appears (booting up) for like 1 sec and release them. When you actually see the "android out of box" logo, press the menu button (the one at the left of the home button) and wait for the list to come up. You can choose the option by pressing the volume button (+ = up and - = down). To confirm your selection, press the home button.

Good luck!

You can keep it in your computer or keep it on your phone, up to you though 
"You should always keep one good Nandroid backup on your phone just in case" - quoted from http://www.goodandevo.net/2011/10/how-to-c...ed-htc-evo.html

For custom roms, you can try out the Cranium Rom, BroodROM or ThunderBolt! (made by our very own lowyat forum member, pikachu01). I'm about to try out the new Cranium RC8, will post up the steps and scores here when I'm done 

Yep, you'll have to reinstall them but most of the tweaks are in the custom rom itself so don't worry about it 

RC8 is just being released today (like a few hours ago) and I'll be testing it later on. It's up to you really    I've just finish flashing to ZSKP6 ROM and ready to flash to RC8 

RC8 is just being released today (like a few hours ago) and I'll be testing it later on. It's up to you really    I've just finish flashing to ZSKP6 ROM and ready to flash to RC8 

Well, apparently I have the same problem LOL! but solved it already 

Just go to recovery, factory reset and choose install zip from sd card again then it shall be fine 

Yep! Flash back to asian stock rom.  Then you're good to go!

Which version of FeaMod you flashed with? Did you flashed FeaMod after you flashed RC8 though? Well, the latest update available via Kies is DXKJ2 so I think it'll be better to flash to that one better sending back for warranty though 

You'll still get to keep your FeaMod since it's not a kernel to begin with. 

"Instructions-

*Place the .zip in your Sd card.
*Go into recovery mode(U must have FeaMod Recovery to use this!)
*Flash the zip.

Pretty easy,huhh?"

source : Cranium Kernel V6

You can get the Cranium kernel v6 from the link above as well 

*Update* well, that much be feacore (kernel) without OC/UV then. hmm...well, my battery life so far so good though.

Usually is like this or after you install the RC8 and you get this problem? Mine is all good like before though. Certain rooms have bad wifi signal and service signal (digi/maxis/celcom and etc) due to the infrastructure of your house and as expected that phone wifi signal is not as strong as what we have on laptops or pc. If your signal is still weak after you step out of your house, that's a problem then

it will if you're running too many app and if u're on long phone calls. if standby still hot then i think there's a problem. how about after flashing to rc8? still hot?