Changing Your Home Page
Your home page is the page that opens when you click the Home button in the
Personal Toolbar. Depending on how your preferences are set, it may also be
the page that opens automatically when you launch SeaMonkey.
To specify your home page:
Open the
Edit menu and choose Preferences.
Click the Browser category.
In the Home page section, perform one of the following:
Type your home page's URL (web address) in the Location
field.
Click Use Current Page to make the page currently displayed in the
browser window your home page.
Click Choose File to select a file from your computer's hard
drive.
Tip: To specify your home page quickly, drag the bookmark
icon image of bookmark icon from the Location Bar to the Home Page
button on the Personal Toolbar.
That is how I get to it on XP, I found that by searching "Home Page" in the help menu.
Hope it helps.