Printer needs a few minutes to warm up in the morning or if it hasn't been used in a while. The printer basically goes into sleep mode if it sits over so many minutes without being used, so it may take it a bit longer to get your items printed. This is particularly true in the morning after the library has first opened.
Also, if you are printing PDF files or other image-type files it could take longer. It's just the nature of those types of files and can often take a bit longer.
If it takes longer than 3 or 4 minutes to get at least the first page of your print job it could be a problem with the printer itself, at which time we suggest to you either go to the computer monitor - or if someone is not on duty at that desk check in with someone at the circulation desk.