Adding Affiliate Adverts to a WordPress Theme

Hi all!
I have recently installed two WordPress blogs and, for one, I purchased a theme through elegantthemes.com. The theme itself is gorgeous but I am finding it not so straightforward – the ftp upload is more complex than simply uploading the them and activating it.
Now I am looking to install both Google adsense and a number of affiliate advertisements – ideally the adsense under the header and the affiliate ads on the sidebar.
Any help is greatly appreciated!!!
Pam