Best practices for EHP

HI all,

We have upgraded the client system from 4.7 to 6 .Now we are in the process of appyling EHP's.We also want to go for AS java.So we wanted the best practise and recomended procedure by SAP.If we want to go for EHP 3 ,So we should we go for java add in now or after going to EHP3 .Where can i find the best practices.