Hi,
Using PhoneGap you can develop for almost any platform, but to target
a build on iOS you will need a Mac since you need to use XCode. That
said, the idea behind PhoneGap is that the same code is used across
all of the apps, so what I suggest is perhaps targetting Android so
you can use any operating system. We can then port the code to iOS for
an iOS app build.
There are simulators for the different devices, so you don't ened the
real thing. Of course, if you have an iPhone, iPod touch or an Android
phone, it would be easier to make sure it runs well.
The best place to start is checking out the Phonegap tutorials and
getting up to speed on jQuery and JSON/XML parsing.
cheers,
Steve