Down in your shortcut panel where you have a button for mail, calendar, contacts, note, etc. You will find a Folder List shortcut. Click on the Folder List button and you will see Public Folders on bottom of this list. This is where you go to access your public folders. Right click and click on properties to change permissions to your public folders.
What version of Exchange are you using? Are you an Exchange Admin? You can use the PFDVAdmin tool to make changes if you are an Exchange Admin, otherwise you will have to ask the admin to make the changes you are requesting. PFDVAdmin is installed on your PC, not the exchange server and it works with Exchange 2000, 2003 and 2007. When you have created the new folders close and re-open your outlook and try a send/receive. You should be able to view them.