The best sites to use to place your banners on will be those that are linked or close to your market but not in direct competition. For example, if you were selling stationery, then a site with office furniture or office products would seem like a good choice. The idea is to complement the two sites so you are advertising to your target audience.
You could also use a shopping directory site – but here you will need either a niche market, or a unique selling point to stand out from other companies advertising the same items or services. If this is not possible, then the design of the banner will have to stand out and be the reason customers choose to come to your website. This is more general or random advertising.
If you have a tight budget, you can try exchanging banners or links with other websites – this is usually free advertising, or costs very little, but the exchange sites are not always complementary businesses, so it can look a little strange, particularly as you may not have much input on the appearance of the banner on your site, and you also may have no input on where the banner is advertised on the exchange site. {joscommentenable}
Once you have a web banner – take a look at how to make it work effectively for you - Rapid Banners 
