Sure. Depends on the information you want.
Do you want to know when the owner bought the house?
Do you want to know how much he/she paid for it?
That information is typically online with your city or county tax assessor's office. You usually can figure out if the seller has refinanced from the same source. In many areas, for instance, it'll show that Joe Smith bought the house for $100,000 in 1990. Then it'll show another recorded deed by Joe Smith in 1994, with the sales price blank. That's either a refinance or, possibly, placing the house into a trust.
Sometimes you can check for liens online, or notices of defaults. Usually, however, you have to go down to the courthouse to track that information down.
Similarly, if the seller put on an addition to the house, you can go to the city or county permitting office and see whether permits were pulled, or whether the owner did it without permits.
A Realtor can usually uncover additional information. Let's say the tax records show the home was purchased for $100,000. It's possible that the seller contributed a seller's subsidy--let's say 3% (or $9,000). That means that although the tax records will show a purchase price of $100,000, it actually cost the buyer only $91,000. Also--depending on the MLS system--a Realtor often can determine the amount of the mortgage(s) on the property. So the person bought the home for $100,000 with a 3% seller subsidy. How much of that $91,000 was actually financed?
And there's plenty more you can find out online. Just do an online search using the property address, for instance. I've uncovered everything from people convicted of crimes to law suits against community management.
Now, having said all this, you really don't need most of this information unless you're an investor working certain specific strategies. Generally, as a "retail" buyer, what you should focus on is the fair market value of the home. A Realtor can do a CMA for you to determine value. Let's say, using the example above, the CMA for that house comes out at $130,000. That tells you to pay no more than $130,000 for the home. So your offer probably ought to be less. One additional point: Your offer should not be based on the listing price. Maybe the house is listed for $130,000. Maybe $150,000. Maybe $160,000. Doesn't matter. Your offer should be under $130,000, because your offer should be based on the home's value.
So let's say you offer $120,000. In the example above, the seller might accept it because it's above what he paid. Let's say the seller actually paid $130,000 and it's listed for $155,000. You offer $120,000. It probably won't be accepted because the seller is likely upside down on the mortgage. So what? You don't want to pay any more than $130,000 in any case. Now, maybe your website research has uncovered all these facts. That's fine. You can still make your offer.
It can, of course, work the other way. Assume it's been owned by the current owner for 30 years. You check online, and you guess it's probably all paid off. It's listed for $135,000, and the CMA is $130,000. That's pretty fair. Still, if it's all paid off, you might try a low offer--let's say $95,000. You know from your research that the seller COULD accept your offer. Probably won't, but it might be worth a try.
One other point: Although the seller may not wish to share information with you, it's possible that your Realtor can obtain that information anyhow. I gave the example, above, of a seller subsidy. There's plenty of information that Realtors can obtain (legally, ethically, and morally) to help you put together an offer. Point is: You don't have to be your own detective for much of the information.
Hope that helps.