From the Illustrator File menu choose Save As… For Format choose Adobe PDF (pdf).

For Adobe PDF Preset: select [Press Quality]. Compatibility: should be Acrobat 5 (PDF 1.4). Optimized for Fast Web View should be unchecked.

* Select Marks and Bleeds from the left column. Type in the bleeds for the document in the Bleeds section at the bottom, usually 0.125 inches.

Select Output from the left column. Set Color Conversion to No Conversion.

Select Summary from the left column. If no warning messages are present, select Save PDF. If in the Warnings: box there is a message about The Document Raster Effects resolution is 72 ppi or less, select Cancel. 
From the Effects menu in Illustrator, selectDocument Raster Effect Settings… In the Resolution box, select High (300 ppi) and select OK.

Got back to the beginning of these instructions to save as your Illustrator document as a pdf.