This depends on where your data is from. Is it an input log in ASCII format? Is it a core description?
Try the import las, or import as well log ascii format (the later gives you more control)
If you want to interpretate the log manual, just add a new discrete
log (right click on global welllog folder) and make sure it gets a lithology template. Then display it in a wellsection and use the discrete log painter to paint the different lithology classes. Search in the help for log painting and you'll see what I'm talking about.
hope this helps.