The unity integration is fair to middling. Your main source of pain is going to be .meta files - if people check in assets w/o metas you're likely going to see assets that don't work on some machines and do work on others. While the Unity integration tries to manage this for you it's not flawless, and people will always check stuff in and out manually.
Learn how to write Perforce triggers and make one that rejects checkins of assets that don't have matching meta files. That was the only thing that saved us from collective harakiri
Have strict naming conventions - PARTICULARLY for casing - because unity meta guids will diverge if different users have differently cased paths: Assets/A/B/C and Assets/a/b/c generate different guids for all of the folders, even though windows considers them the same path. You can configure perforce to treat A/B/C and a/b/c interchangeably, but it will still respect the casing users have on their own machines which can vary for all sorts of reasons.
Lightmapping is another constant irritation. When you rev lightmaps Unity tends to delete them rather than checking them out and updating them. Same for light probe data. So if you go that route, you'll probably need to write a little helper for users so they don't lose work.
Unity has a bad habit of silently checking out large numbers of files (usually because of guid or file casing conflicts as above). You probably want to configure perforce to ignore unchanged files. You also want to make sure that you DONT set auto-locking (ie, you-cant-check-out-because-i-checked-out) or people will be blocking each other left and right.
If you're not familiar with the perforce api.... well... it's icky. You need platform specific binaries (even for the python bindings) and it's very old school. Besides learning the commands you'll need to learn p4's odd ideas about how to answer your questions. It's not exactly hard, it just takes a while and constantly violates the principle of least surprise