The preparation of a surface is 90 percent of painting job. Even the highest quality paint won’t adhere properly if the underlying surface is not prepared properly. Good surface preparation means clean and smooth surface.Allow newly plastered surface to mature for a period of at least 6 months before painting. Rectify existing surface problems such as dampness, cracks etc. before actual painting process. See the link below
http://www.gharexpert.com/articles/Paint-2011/Checklist-Painting-Work_0.aspx
http://www.gharexpert.com/articles/Paint-1641/Surface-Preparation-Painting-Tips_0.aspx