Have you ever read an online newspaper like the New York Times?
Thats a bit unfair, because the NYT tends to be pretty difficult sometimes (like the "pope-is-dead" articles)
Have you ever watched a DVD in English? (both with or without subtitles)
I can recommend following DVDs in the following order

(arranged by grade of difficulty, starting with the easiest

)
Dude, Where is my car
I, Robot
Sesame Street (some episodes where Ernie has the biggest part *g*)
Back to the future
Smallville
Eurotrip
Sonic X
Robin Hood - Men in tights (well - it fits this place if you ignore Hatchu

)
Cruel Intentions
Married with children (I don't know why I put it here, but I was told that it is difficult to understand)
Super Mario Brothers (sometimes spoken pretty fast)
Harry Potter (1/2) (British English - most ppl find that most difficult)
Forrest Gump (because of the accent)
Thats how I'd arrange it. As always: there are better ways to arrange this list

Anyway, if you understand those without subtitles and if you understand about 95% of the content, I'd say you are good
But also important is "speaking english", which means that you should be able to make up sentences (with a mostly correct grammer) in no-time.
I am always open for correction :D