Build Banners of varying dimensions

I am needing to get some banners made for my website. A couple will be to do some promotion on the website itself for some of the different aspects of the site. Most will be for advertising of the site by other means. The sizes that I am looking to get that will post on my site are 468x90 and 160x600 For advertising elsewhere I am going to want 300x250, 160x600, 468x90, 468x60 and 120x60 They dont need to be overly fancy, just very informative and creative. Need to be somewhat eye catching and most of all explains and shows what the site is all about. For the ones that are going to be for posting on my site they are going to be for promoting products such a groups and chat. Basically to create awareness of the offerings and to hopefully get people involved in the site. The website is [login to view URL]