Well my dog is 5 years old and he's a cocker spaniel. I really want to get an inside dog for myself (my family owns this dog, but he never really pays attention to me and my brother and dad give him playtime and affection) because I'm kind of lonely at home everyday.
It's our fault we never socialized him, but he doesn't let other dogs onto his territory. We let a puppy on his yard a while back and he bit it's leg and it bled. He rarely actually FOLLOWS our commands but he listens pretty well to me. At the park he's a-ok with other dogs, mostly leaves them alone.
How do I socialize him? (We keep him outside because our house is kind of cramped so there no room for him to run around and he's REALLY hyper. Where I live, the weather is usually pretty uncomfortable and/or hot, so I don't like going outside.)

Before socializing with other dogs, you need to have him listening to you. I would suggest obedience classes. Also are you walking him, that would help with the hyperness and maybe he could be back in the house. When you get a dog you are responsible for more than feeding and vet visits. A dog NEEDS daily walks and play time.
Susan

My mom (I think) will try to get him in an obedience class. He can stay in the house for a while as long as he has gone to the bathroom.
If I get a new puppy, it'll be summer so I'll have plenty of time to spend time and train this new puppy.

I'm sorry to sound like the bad one here but...

when you say "the weather is usually pretty uncomfortable and/or hot, so I don't like going outside", how do you think that poor dog feels? It has how much fur on it! How are you going to take the new puppy for a walk if you don't like going outside? Dogs need daily walks, and not just a quick lap around the block, my dogs go for at least an hour walk a day and then some "free time" in the field, I try and take them on two one hour walks, but that extra hour isn't always possible.

To be honest, I got another puppy without thinking enough into it, my puppy is now my problem child, it is getting better with socialization and training, but what happens if your pup is aggressive to humans? Are you going to put in the hours and hours of work to fix it? My oldest dog has some aggression problems with dogs but he got along great with my young pup, well now they fight occasionally, do you know what to do if your dogs decide to fight? My one dog is much larger than my other one, so either I break it up, or my little one is going to get hurt, and I don't want to see that (I know they say don't, but it is a lot easier to grab the scruff of the larger one and yank him off than to lose a dog, even if I get bit).

Before you get a puppy please think about this,
1. Do you have enough time to take the dog for a daily walk?
2.Do you have enough time to train the puppy? Housebreaking is a long process
3. Do you have enough time to spend with the puppy?
4. Do you have enough money to pay for vet bills?
5. Do you have enough money saved up for emergency situations?
6. Is the puppy going to be in a safe environment (Leaving it outside in "uncomfortable" weather is not an option)?
7. Will you be able to afford to feed the puppy?

Please think about these things before getting a puppy!