help

I have serviio installed and working with nokia n8 and sony bravia tv , i have set up some feeds and have plugins in the correct folder . some feeds work but not many im unsure how the rtmp works(i have url snooper and rtmpdump) and how i get the url to put into serviio ,i have tried the rss feeds in the forum and only 1 or 2 work for me. Any help would be very much appreciated!