This link has all you need:
http://forum.androidcentral.com/opt...optimus-v-rooting-roming-modding-hacking.html
The market still works like normal for getting apps. Rooted doesn't change anything.
As for roms... Each has it's pros and cons.
That guide has a complete listing, but for someone new, and unsure, I would recommend Rodimus, as it's a very good place to start, as it's a complete, somewhat current solution where everything works. No muss, no fuss. Beyond that, they all are good and have their place, but you need to know what you want first. AOSP has some nice tweaks, Bumblebee seems to be the hardcore tweakers rom of choice because of how raw it is, Sllide has a nice theme and features, Nameless has some new groundbreaking features, and Harmonia seems to be just a really good, everyday type rom that everyone just seems to find pleasant.

It's fast, has nice features, but it's not bloated, and has loads of room for apps.
As for recoveries, taken from Harmonia's info section...
Recommended recovery:
http://forum.androidcentral.com/optimus-v/61431-xionia-goodies-optimus-v-edition.html
It is what is used in Mmmark111's RomTools found here:
http://forum.androidcentral.com/opt...3-1-ex-recoveryflasher-tons-new-features.html
These are the most universal recoveries, they seem to work with almost everything out there.