No, Leela, there are no rules.  If you want pulp, almost any paper will mash up well (follow the recommendations in the tutorials and articles).  If you want to laminate/layer, you could always try a few layers over a piece of plastic before attempting anything bigger.
Mainly, newspaper type and thickness will mould well and leave you with a very smooth surface, as long as you lay it carefully.  If you want to build a strong structure, use bond and kraft papers.  Old documents etc. are ideal.  The ink is no problem.   
DavidO