I did my undergrad and got my Master's from Texas Tech, so I am quite familiar with the area. I also grew up in a nearby town, so let me know if you have any more questions. Lubbock is a pretty standard college town. I love Lubbock, but my wife hates it. Most of what college students do is go drinking. I am not saying that they are all alcoholics, but thats just what they choose to do. On main street near campus is where a lot of people like to go, mostly undergrads. There are more bars around town that are aimed at older people and grad students. Until this past year Lubbock was a dry town, meaning you could only by alcohol at bars inside city limits, but that was changed so now people can buy it at any of the grocery stores. I assume this will make the bars less crowded. There is also the depot district, which is where all the clubs are where people go dancing on the weekends. If you are not in to that scene there is still plenty to do. There are a couple of movie theaters in town, and one drive in theater which I really enjoyed going to. Lubbock also gets a few big concerts a year. There is also a Main Event which has bowling and laser tag and stuff. For weekend trips there are a few places nearby to go camping, hiking, and fishing. I never did any of that so I am not familiar with it but I know it is possible.
For the question on where to live, it depends on if you are looking for an apartment or a house and if you want roomates or not. A general rule is to stay west of University and south of Erskine. A lot of undergrads live in the Lynwood Townhomes, which I really think is a good place to live, but it can get quite loud with the amount of people who live there. If you want something more quiet you will probably want to look further from campus. I had a house to live in so I didn't do a lot of looking. If you any more specific questions about this let me know, as I know quite a few people who still live there.
The weather in Lubbock is hot and dry. It doesn't rain a lot, and it gets cold sometimes, but for most of the year it is hot and dry. And windy. You will probably get one day of snow a year which is nice.
I know this was a bit of an information overload, so if you have any more specific questions post them here or send me a PM.