You don't have to own land in Second Life to have fun. But owning (or renting) a little bit of the virtual world, where you can have your own private (well, mostly) little retreat can add a lot to your enjoyment of SL. I have owned land since very early in my Second Life. There was one brief period where I was "between homes" and I felt very uncomfortable. I guess I don't take well to being rootless.
I like having land, with enough square meters and free prims that I can be creative whenever I want. I like having a pretty home, where I can invite guests to sit and chat. In fact, I like having more than that...I like having enough land that I can rent some of it out to other residents. I like having neighbors that are also friends. My tenants have a stake in our shared land, and I like the feeling of community that comes from that.
Maybe I am just projecting my own personal preferences, but I think that anyone who really "gets" Second Life is eventually going to want some land of her own. So let's talk about land!
Land is the ground basis (sorry about the pun) of the Second Life economy. You have to have land in order to bring objects into the world and have them remain there. Land supports prims. The more land you have (in any given region) the more prims you can have there. A 512 square meter parcel can have up to 117 prims on it. That's enough to build and furnish a very modest home, if you choose your objects carefully. A full region, 65,536 square meters, can have up to 15,000 prims. Linden Lab charges between $195 -- $295 USD per month for a full region. Those basic facts are what drive the SL economy. Businesses, whether stores selling content or land barons renting out parcels, must make enough money to cover their monthly land costs to Linden Lab (with enough left over, hopefully, to show a profit.)
There are lots of ways to own land. Perhaps the simplest is to buy a Premium membership and apply for a free Linden Home. There are four different styles you can choose from, and if you get tired of one, you can abandon it and get another. The Linden Homes are on small parcels (512 square meters), and you only have 117 prims to play with. But, unlike other 512 m2 plots, the prims of the house itself don't count against your 117 prim allowance. Although the houses are jammed close together, you can use ban lines and parcel visibility restrictions to gain a measure of privacy. My major objections to them are that 1) the regions they are on are so crowded that they tend to be very laggy, and 2) there are a lot of restrictions on what you can build there. No skyboxes, no stores or clubs, and you can't modify the home itself. About all you can do is decorate the interior. But even with the limitations, a Linden Home is a good way to get an introduction to land ownership in Second Life.
You can read more about Linden Homes here. http://community.secondlife.com/t5/English-Knowledge-Base/Linden-Home-overview/ta-p/700103
That's it for Part 1. In Part 2, we'll talk about Mainland.