If your compute can handle it, internet is fast enough, and you have the patients; this is going to be a blast for you.
When you first make an account, you choose what avatar you want and its gender. For both female and male, there are different verson of the avatar. These versons include different skin colors, outfits, and shapes I think. After your account has been created, you are sent to one of multiple introduction islands (I forget the name of the islands). All of these introduction islands are the same, and they all introduce you to the basics of Second life, which is very nice, I could easily name some compition if SL who fail to give their new users a proper introduction/ tutiorial. But I wont do that. These islands teach you how to move, how to move the camera, how to chat, how to fly, how to teleport, how to sit down, and if you computer can even handle second life (what I mean by this is; when you first start second life for the first time, you'll show up in this building, with multiple rooms that are on a path, you will have to do the rooms in order. Anyway, these rooms have objects, some that are animated and some that arent, with high resolution. If your computer chokes up and kicks you off, sign back in, if it still chokes up, that means your computer cant handle a Second Life). After that, you are teleported to SL's grid, other wise known as the world map. Which, for your information, is huge! Since the world map is mostly made by users like you and me, some places might be poorly modled or detailed, but I have yet to come accross such a place. Most places are really detailed and are beautyful! But if your computer can kinda handle sl without constant crashed, you might not be able to see sl in its best. But that doesnt really matter, since the beauty can be seen even without super high detail.
Now granted, it can be difficault to find people to socialize with, but! thanks to secondlife website's world map (and the great map within the sl view 2), it isnt too hard to search up "social" places. Such social places include but certainly arent limited to; Clubs, sandboxes (the place where you can test build and rez the products you bought off the market place), some stores, greating areas, and events.
I will come back and fix my review of this since I am running out of time, later.
In summary, SL is alot of fun, you can be whatever you want to be, make whatever you want to make, and be whoever you want to be! Its free!