If you are using xyscan for the first time I strongly recommended that you take a couple of minutes and go step by step through this documentation. At least you should read the following chapters: Introduction, Loading Plots & Images, Moving the Cursor, Setting Markers, Scan Settings, and Scanning. Use a good quality plot and test things out as you read along.
If you were using xyscan (version 2) before you should be able to get familiar to the new interface and features rather quickly. Have, at a minimum, a look at the What's New? section.