If you're writing to lansinoh for freebies - how about some nursing pads? I definitely had times when I soaked through mine and if I didn't have spares - mess! With regards to magazines, I think a mix of parenting and non-parenting magazines would be nice. Once you get the room started, you could put up some sheets of paper asking moms for further suggestions.
Also, it's nice if the room is not too cold.
Newmomma, that's funny what you say about the housekeepers barging in - the lady who cleans my office walked in on me one time while I was pumping and seemed completely unfazed!