I use T-pins in the binding seam. I bought them for wet blocking which takes longer than overnight to dry, but they are fine for dry blocking as well.
Sue, here's a descriprion of quilt blocking. It should answer all your questions.
http://academyofquilting.com/library...sary/blocking/
ETA: I think almost all sewing pins are rustproof these days, but I could be wrong. I haven't seen rust on a pin since the 60's.