Go to your local sporting goods store and get a copy of the hunting regulations. Under general and under deer, it will have all the info you need. (including the 1-800 number). Or check out this link
http://www.mnr.gov.on.ca/en/Business/FW/Publication/MNR_E001275P.html
Edit to add
Let's start from the top.
First get your outdoors card (hunting version)
Now, depending on where you live/hunt you are either in a controlled hunt area (SW Ont) or a non-controlled aka regular area.
If you hunt in a controlled hunt area, you must call the 1-800 # (or submit by paper (mail)--which you can get from a Service Ontario centre) and apply to be in the controlled hunt. This has to be in by Sept 02 2008. When you do it over the phone; you are not buying a license, you are just entering the draw. If you get chosen to hunt, you will get a validation card in the mail and you need to go to the local licensing place (ie sporting goods store or MNR office) and buy your license (aka tag). So When you hunt, you need to carry the validation card, your outdoors card and the "tag"/game seal.
Remember only enter the draw once, by phone OR paper NOT both
If you are in a regular area (non-controlled hunt), you can do one of three things. (1) Call the 1-800# and buy your "buck" tag and enter into the antlerless draw. This has to be done by July 31 2008. OR (2)Go to your local licensing place and buy a "buck" tag. Included in this tag is a form, which you can send into the MNR to get entered into the antlerless draw. Make sure you are entered by July 31, 2008. Again
Only enter the draw once, DO NOT do it by phone and paper. Option (3). Buy your "buck" tag and do not enter the draw, it will only allow you to hunt antlered deer.
As to additional game seals. I believe what they are trying to say is; You must have a current seal/tag, before you can apply or buy a second one.