Total newb here - help with installing CM11 on stock phone please topic

I have a RAZR i which is running the stock UK 4.1.2 firmware, and I'm tired of the long pauses and lags when switching between certain apps (i.e. Chrome browser) and returning back to the home screen. I was going to hold off and wait for the official OTA 4.4 upgrade to see if it would improve, but I'm running out of patience with Motorola.

So I figured it might be a good idea to try a custom ROM, but I have a couple of questions:

a) Can anyone suggest a good all-round custom ROM? On previous phones I've often used CM - is the Razr i CM11 build a good every-day ROM?
Is there a complete start-to-finish guide for installing custom ROMs? I've looked in some of the help threads but I'm still quite confused.

Thanks in advance, guys!