Language / Two extremely helpful grammar websites for Polish [2]

I will begin by saying I am sorry if this is a re-post but I just wanted others to know about these two websites. I am very new to Polish and only seriously for the past month have been really trying to educate myself and these have been invaluable.

grzegorj.jzn.pl/gram/gram00.html

polish.slavic.pitt.edu/~swan/beta/

The first one is great for all kinds of grammar review and the second will give you full declensions of any noun and adjective you can think of plus full conjugations for all Polish verbs and is also a ENG-POL and POL-ENG dictionary.

Again, sorry if someone else has already posted this.

One more thing, a quick grammar question. If I want to tell someone that is my age and that I am close with "you are a good friend" I would say "Jesteś dobrym kolegą" and my question is this. Are dobrym and kolegą in the instrumental case because they follow the verb być (jesteś)??

Thanks!!