Nchantd,
I use 1000 x 680 as my maximum finished size*, so it will
play (without scrolling) in a browser with system resolution set at
1024 x 768.
Used to be that 1024 x 768 was the highest setting for some
laptops. Now I assume that because many of my end users are in the
'bifocal' stage of their lives, they don't set their system
resolution much higher than 1024 x 768.
If you're publishing to be played in Flash player, you can go
to higher dimensions.
I suggest a dry-run capture/publish and then a test by a few
real-world end users. Then decide.
* BTW, for most of my projects, I capture at 1000 x 620 and
resize to 1000 x 680 so I can add a 30-pixel graphical header (with
room for text and the Captivate drop menu) and 30-pixel graphical
footer, (with room for text and the playback controls.