[pdftex] Problems using Graphics from Adobe Illustrator

[Stueker, Dirk]

I am using Adobe Illustrator Ver. 10 to generate pictures for a
pdflatex-document.
Unfortunately the result is disappointing.

My questions:
- where is the difference between the .pdf and the .ai format (the latter
should be compatible)?
- how can I directly import .ai files? \includegraphics says "unknown
format"
- My main problem:
  The print-area has an effect on the output. I expected the pdf-format to
be independent from
  the selected printer. However if not set properly the graphic seems to be
cut at some point 
  or contains white margins.
  How can I export *all* objects that I drew in Illustrator and restrict the
output area to the area where
  objects are (is there a bounding box feature).

Any help is really appreciated.
Thanks in advance 
Dirk Stueker