World of Warcraft is the most successful MMO to date. The storylines flow well, and open ended gameplay lets you do what you like, be it PVP or PVE or if you just want to play the market (yes people do that). I have been playing since vanilla, this talk about WoW ruining your social life is all a matter of perspective, WoW in itself is a social game, if you want it to be, in the end you are responsible for your own choices in life. I choose to play WoW rather than go out drinking, but all good things come in moderation. For me it got to a point to where I needed a mental break from the game from time to time, was heavy into raiding every night and that took alot of personal time, so I took about 8 months off as RL got too busy for me to dedicate the time I wanted to the game.
Finding the right guild for you is almost essential, choosing the right realm is also essential. Pick a realm where your side has about 20k+ players, as it makes for a better market system and a generally more populated sandbox if you dont really want to play with others then low pop servers are ok but personally I like a busy local channel. Also pick one in your time zone, I am in central zone and play on an east coast time zone so raids and such happen earlier in the day for me so I dont have to stay up late if it runs over, much the opposite if I played on a West Coast server. For information on WoW Realms go to www.warcraftrealms.com, they keep a running census of all the realm populations and divides them by horde and alliance. Currently Area 52 is good for Horde, not too sure for Alliance. If you want to play horde I can help you get started there.
As for the price, right now Blizzard is selling mists for $20 and the entire and the rest of the expansions for 15 bucks, so for a total of $35 you can have all the expansions.
The lore itself is great and the questing mechanics include vehicle fights, some cut scenes, and a world where the artwork is amazing.
As you are unemployed, been there done that, playing WoW is a good way to waste alot of time.
Just keep it fun and it will be fun for you.