I'd been playing since the beginning of the final, 3rd open beta (or the first one if you count 2238 version only) and had a longer break only to come back into play recently.
It's too late for you but I think the best way to play the game is starting with almost no knowledge the game mechanics (besides the stuff that is obvious for anyone who's ever played Fallout), being lost in the wasteland, learning how to survive, avoid being killed every five minutes, how the importance of different skills changed from original games, how the crafting system works, how you can level up and gain any money while you start with almost no equipment and easily lose anything you gained, which towns are (relatively) safe... When you master the game, it loses a lot of its chaotic, anarchistic charm.
For the same reason I advice not to join any gang right after starting playing. It becomes too easy to grab an armor, a gun, some ammo and level up when you have other people supporting you. Of course, when you are not a newbie
Basically, it's a MMO (omg, lol, you stupid, of cuz it's a MMO! (shut up, motherfucker, let me continue)) and despite being called a beta, it's still rather in an alpha phase.
The first means it's gameplay on its own is rather mediocre, you'll have to grind to achieve anything and most of the fun comes from interacting with other players, chatting, being killed for lulz, showing how cool you are because you have a combat armor and a plasma rifle (which you lose in a minute after that because there are other players who'd like to get that shit), forming a gang, travelling in a group and terrorize the wasteland...
The latter... well, there's not much content at the moment and most of the work is concentrated on balancing the current build and fighting with bugs. For example, there was a decent sneaking system but the implementation of FOV caused some huge lags and until the problem is solved, we are playing with some fucked mechanics that allow good sneaking build becoming almost invisible. Recently we were trying to finish the only one (!) quest that is designed for a group of players. It was quite fun, despite the fact we failed hard - or maybe because of it :D - but the game needs much more such content.
But it has a lot of cool features like open PvP, full loot, factions system, bases, crafting system, graphic, music and sounds from Fallout, improved SPECIAL.
If you have any detailed questions, it's best to visit #2238 channel on irc.forestnet.org. And if you are there, you can also come to #rpg-codex which is a headquarters of The Repo Men - a gang created by some of th Codexers (currently only me and Redeye are playing) and some of the ex-Unity members (gang from a previous beta, its other are now devs and GMs).
No permadeath, tons of griefers, tons of high-level characters, grinding, weird rules. Completely un-Fallout-y.
Josh Sawyer disagrees.
In a way, its Ultima Online-like griefer brutality seems to be pretty appropriate for the Fallout setting. At its core, Fallout is about humanity's limitless passion for snuffing the life out of people for any and every reason. Gangs of assholes stomping another player's brahmin for profit and amusement seems to be a lot more fitting than farming mobs of geckos.
And, as an addition, some pics I found on my HD and ImageShack account and decided to share:
GM shitting all over our base and changing our shapes.
Hmm, I'm not sure when it was taken. Probably some pre-wipe massacre or creative use of (now resolved) bug that allowed to make guards go mad.
Being owned by Ruskies.
Don't remember what was that too. Either some GM controlled event or somebody gathered so much ghoul slaves. Now the number of slaves/mercs/brahmins you can have is restricted.
Zombie attack on New Reno.
It's us! The coolest nazis in the game!
A result of attacking slaves who were protecting a base. Notice a Codexian easter-egg.
New Reno boxing night.
Terrorism in NCR is rampant (aka Redeye is fascinated with explosives).
New reputation system. I have no idea why almost nobody likes me. I try to be a nice guy.