Why is there smoke under my hood?

[aspiring_author]

I have kind of a dilemma, or at least possibly one. My 1998 Subaru Outback, is producing white smoke. The problem all started about a year ago when it had a sort of funny, burning rubber smell to it under the hood. I talked to my dad about it, and he said it was nothing to worry about. However, I noticed that if I went long distances (IE 60-100 miles) that I would see smoke under the hood once I parked. Now, it's worse than before, it only takes about 5-10 miles for it to start smoking. Also, now when I go for long drives, it smokes a lot more than before. I sort of experimented, drove for about ten miles, had the fan and air conditioner off, and found out that I think it didn't smoke or overly heat up. I only did this once, so I don't know if it was just by coincidence. I'm kind of worried about it, I'm afraid that I'm going to be stuck on the side of the road sometime, or that it will blow up. It also makes a squeaking sound quite often, like a belt or a break is about to go out. It does it just randomly, for instance: sometimes when I have the air conditioner on/off, when I first start it, when I'm turning, or when it feels like it (I guess). So, I got the belts replaced, but it still makes the noises, it's very loud, and a little embarrassing. I don't know much about cars at all, so I'm very confused, and any advice would be greatly appreciated. I take fairly good care of it, and make sure that I always get my oil changed (which I did a couple weeks ago). There is corrosion on the battery, and the engine is quite dirty, which I have no idea how to clean and would probably ruin something if I did. I love driving a Subaru, but I'm a little weary about driving this one. Anyone have any thoughts about what's going on? I tried to be as detailed as possible without going overboard. Sorry if this was too long of a note. Thanks for any help!
-Cluelessaboutcars-