[fpc-pascal]Delphi/FPC cross-compile

[Alan Mead]

My Delphi experience is limited to going through "Delphi for Dummies"
a few years back, I was once a proficient Turbo Pascal 5 programmer. 
I've been using FPC.. one of the things I really like about it is
being able to compile the same code on Windows and Linux.

I've been given a copy of Delphi (8, altough I may exchange it for 7)
and been asked to create a class that implements some non-visual
functionality (it will perform searches on textual data, like
Google.com).

I'm dreading giving up Linux compatibility.  Is it possible that I
could create the required class in such a way that it can be compiled
by both Delphi 7/8 and also by FPC?  If it's possible, is it
*reasonable* that I do this as a Delphi novice? Got any tips on
things to avoid?  I'm not even sure how I will do it without a
command line....

Any recommendations on a good book for my context?  Using FPC and the
FPC docs, I tried making a class over the weekend and I did something
majorly wrong... I don't grok the difference between an object field
and a class property.

Thanks!

-Alan