Newbie Questions

Just starting using Zoho to track my contacts. I want to enter some data such as when a catalog was sent or when an email was sent. Which is the best method to do this? In looking at tasks or events, I have to record a start time and completed time or date which is obviously not needed on past events or even on future ones really. Is there a better way? Thanks!

Let me clarify in that I want to have some history in here of past events but don't see a good way to enter those I previously sent an email or a catalog to.