Say a model contacts you through this or another model/photographer networking site, asking about working with you. No mention of money is made, so should one presume they are wanting TFP? Or do models requiring pay for shoots do this, then ask for pay after you express interest? Was I supposed to say I was interested and then inquire about rates?

I know a few photographers have mentioned models approaching them for paid work, but I understood that NOT to be the common practice.

I had a very experienced model contact me on another site, and I emailed back what dates she has available that will work for me, but now I'm afraid she'll come back and say, "I scheduled you in for this date, now you owe me $X!" (She does a lot of nude work, and her profile says her compensation "depends on assignment.")

I hope this isn't too stupid a question, but model shots/fashion is a new genre for me. I'd like to avoid making TOO many faux pas.

Don't presume anything.  Ask or make an offer, then take it from there.

BTW, it's not uncommon for models to message out of the blue asking for paid work, it's also not uncommon for photographers to despise such practices.  I suppose somewhere in the middle it works out for some people....

Short, sweet and straight to the point.

Thanks!