Newbie booting up

[rprov@connix.com (Deluxe)]

Please help.
I recently aquired an Apple IIgs from a local school system and would
love to use it.  It came with all the periphials [mouse, keyboard,
3.5" & 5.25" floppy drives, printer ] .  

Here is the problem.  I only have experience with PC's [ not exactly
an expert with them either ] .  When I turn on the Apple a message
appears on the sreen as follows: "check startup device".  Does this
machine boot from a floppy and if so where might I obtain one?

I appreciate any help I get from this group and will continue to
monitor it.  I've long been an admirer of Apple but when it came time
to buy a computer a few years ago I had to think of my son  and what
he was working on in school which is why I went the PC route.  This
Apple IIgs will be my play toy.  I believe it has the capacity to do
everthing I want out of a computer.

Thank you,
Rich Provost
rprov@connix.com