[Galaxy Note 4 General] dr.ketan:
This is for users who first time ever flashing custom ROM.

First you should know difference between stock recovery and custom recovery at least visual difference. So if you don't know how stock recovery looks then first put device in recovery this way

Turn off device. Press Vol UP + Home + Power simultaneously. once you see samsing logo on screen just release power button and keep holding other two. Soon you will see some menu on screen. Note down options available and this is stock recovery. Now move On

1.First make backup of your contacts and SMS. you can do it without having device rooted too. For contacts you can sync with google account OR making backup locally from contact app-menu-Import/Export-Export to (USB/Rxt SD) I recommend ExtSD if you have ext SD card because sometime you needs to wipe IntSD card and may you lose data from IntSD (USB storage) For SM you can use samsung account OR offline with third party app like SMS Backup/Restore

2. Remember that for Installing custom ROM you don't needs to have device rooted. Just only having custom recovery (CWM/TWRP) is enough.

Here is guide to flash custom recovery.

First download tar OR tar.md5 format recovery. If you don't know where to get then seek help from ROM thread which you want to flash and get download link of recovery recommended by respective ROM developer.

Once you get custom recovery in tar format, you needs odin. Also make sure you have installed Kies OR Samsung USB drivers on your PC. I prefer samsung driver only.

Remember you don't connect device to PC while flashing with any extension cable. Simply use single cable to connect device with PC. If it is desktop machine then choose one from backside (direct connects to MoBo

Also make sure your machine's firewall is Off and also turn off antivirus if any you have installed on machine.

Now you are ready to go.

3.Turn off your device. Once it turn off completely, press three button Vol Down + Home + Power to put device in download mode.

Now you will see warning screen and press Volume up to continue

After this you will see green android logo and text Downloading...

4.Open Odin from PC and select PDA (On new version of Odin it will be AP) and navigate to custom recovery which you have downloaded in tar/tar.md5 version. See image below for No3

5.Connect your device to PC and soon ID:COM tab will be turn to different color once device is detected. (see No 1 in above Image)

6. Keep selected Auto reboot and Reset time as shown in Image above

7. Now click on start button (no5 in image above)

8.It will take few seconds to finish process and you will see Pass/RESET msg on first tab of Odin. Now you can disconnect device and it will auto reboot.

9.Turn off device and put device in recovery as said very first on this post. If your recovery is changed from first look of stock recovery then you have successfully finished first task. Now move to post 1 above and part 2 Installing ROM section to continue to flash custom ROM.

10.If even after flashing custom recovery you recovery not changes and same as stcok look you have before flashing then follow this.

11. Follow steps 3 to 5 above and after this uncheck Auto reboot option (no 2 in above image) and finish steps 7.

12. Now this time your device won't reboot auto but when you see Pass/REST msg simply disconnect devie and put device in recovery manually bu Vol UP + Home +Power (as said initially)

13.Now you should have custom recovery. and you are ready to proceed for Flashing custom ROM. Head toward post #1 avove section 2 (Installing ROM)

GoofLuck.