I'm currently using adsence on all of my websites/blogs, but I've been looking into other methods of earning from my websites, one of the sources which caught my eye was buysellads.com - If I place these adverts on my website, can I still have adsence?
There are many sites that have Adsense together with other advertisers and they haven't had any problems.
There is problem only in this case if you use any advertiser's ads having same look like adsense ads (when the other advertiser's ads seems as these are google adsense ads) then its clearly against TOS. So if the other ads have their own look different to adsense ads, then no issue and you can use them