I don't think there are many mods that fix actual bugs in F:NV, but they fix many of the annoying things. Look at New Vegas Nexus for example for mods to install.
My main concern is the User Interface which is just horrible in every way (at least on PC). Increasing the amount of information that can be displayed at the same time does a lot.
Mods I have installed:
- Inventory sorter
- There's also one that shows all health stats in one mouse over screen, but I can find it.
- I'm on my second play through so I installed some cheat to simplify hacking as well.
I'd suggest start playing as normal, and then install mods that help areas that annoy you.