You need to change the scale factor, base point or rotation angle? No problem - all these are easily done before you actually insert your block.
Access the Content Palette from the Tools menu>Palettes or Command (⌘)+2. It's really just a matter of selecting a block from the palette and dropping it into your drawing. The AutoCAD for Mac Content Palette is very simple and easy to use. Tune into the AutoCAD Exchange to see my video on the Content Palette (if you prefer watching over reading). Let's do a quick tour for those of you who have made the move to AutoCAD for Mac (or are thinking about it) so there are no surprises! AutoCAD for Windows has Design Center - and AutoCAD for Mac has the Content Palette.