Smile [Q] How to root and install custom ROM on Sony Xperia SL


I am pretty new to this business. I own Sony Xperia SL and its now out of warranty. I definitely need to root and use some good custom ROM.

Can anyone provide me with a good guide on how to unlock(root) it first and then install a good custom ROM on it?
Which are the best custom ROMs designed for this model?

Current device specification:
Android Version : 4.1.2
Kernel Version : 3.4.0+1.0.21100-313065-g1ccebb5-00193-gcbc50fc
Build Number: 6.2.B.1.96