Just about every website you go to these days is going to have some form of advertising, again this is fine for the most part. These ads will help pay for the site that your visiting. The way these ads usually work is that the person running the site will get a very small amount of money (like under 10cents) for each person who clicks on the ad. There are some sites that will plaster ads everywhere to the point it becomes difficult to click anywhere with out inadvertently clicking on an ad. The site will load with a splash screen with an ad you have to close before getting to the site and the top, bottom both edges, as well as a few in the middle will have banner ads. some of them will expand if you move your mouse over them. Then every time you click anywhere it will throw up ads and pop ups any chance they get.
This kind of behavior is unacceptable in my mind and I tend to avoid sites like this as much as possible. But there are times when you need information or what ever is on the site your accessing. Don't worry there is still hope there is a few programs out there that can help to block those pesky ads.
My recommendation is using an add-on for Google Chrome called AdBlock. Not only do I find that Chrome is a faster browser than IE or Firefox but also AdBlock is built in the browser so you don't have to have any extra configuration or separate programs running. You just need to follow the link above and click the install button and that's it. It is a free and legal program it also comes from the Chrome Web Store that checks it for viruses.
Once installed it will remove most ads that load on websites. So far I haven't seen any negative effects of using this. most ads don't show up at all but other times you'll see boxes where ads should be but are left blank.
Some people will argue that blocking ads will have a negative effect on the "Free Web" meaning sites that generate income by ads alone will be unable to maintain their site if too many people block the ads. I say that income generating ads have already been tainted and destroyed by those greedy people out there that over populate sites with ads as well as tricking and or in some cases forcing people to open ads that they don't want to click on.
On top of that ads are getting to the point where it is becoming a security risk. Some ads don't have the honest motive of selling a product or service. Some ads (not most) have malicious intent of infecting your computer with spyware, malware or viruses. The most common ads like this that come to mind are the ones that try to convince you that you have won something or that your computer has some kind of errors.
Last thing I want to mention on this post is that, First: you haven't won anything nor will you win anything just visiting a website. Second: There is no way a website can determine if your computer is infected or has errors or software problems or anything like that. (only exception to that is there is some sites that can setup scans and such but it requires that you download stuff before hand and I would recommend that you avoid it unless you know 100% it's a trust able site)