Entering a show online is extremely popular. However, this form of entry does have its own set of guidelines.
Often, a show will have the url for the online entry on the Regional Show calendar, the show listing on the CFA site, the show entry clerk's site, or the sponsoring club's website. This url will take you to a CGI form where you will fill out the blanks and click 'submit.' The information that you submitted is then sent to the entry clerk who will enter it as he would a paper entry. In the meantime, you should print out the entry form, and send it with your entry fee to the entry clerk.
You will probably receive an automated email stating that your entry has been submitted. **This is NOT your confirmation!** In fact with some programs there have been problems with the entry clerk receiving the entries, so there is not even the assurance than he has received it.
The entry clerk will usually email out a note that he has received your entry and/or mail the actual confirmation out. If you have not received word that your entry was received within a day or two, email or call the entry clerk and ask. It's often a good idea to drop the entry clerk an email stateing that you've just entered online so that he will know to be looking for it.