Personally I would supply the source file as a .ai or .eps file so that if your customer wants to have some design work done in the future, they have the source file that they can then give to their graphic designer.
Other than that, maybe a 300dpi version .pdf/.jpg for print and a 72dpi .jpg/.gif for web.
Hope you will post some of your designs at some point, would be good to see how you are progressing.
You have all the benefits of a PDF (IE can be used in most programs) but with the extra that it can be dropped back into Illustrator as an .AI - Supplied along with a JPEG so they can use in word.
I normally send a pack with PDFs of all types - logo, logo in white, logo in black (for faxes), symbol only, text only and jpg.
I have just started supplying an avatar version in the pack after seeing a incredibly badly optimised version of a logo I designed on a forum. I've been surprised at how amazed people get when they see I've included an avatar for them.
Also.... HI.... 1st post on this lovely forum! :icon_biggrin:
From a print point of view... an EPS is the best if it is to be used in lots of different ways (perhaps accompanied by a CMYK tiff) if it is going straight to print with no adjustments then a high res pdf is best. Im sure jpg would be better for web, but thats not my area of expertise.
99% of logos will be designed using spot/line colours (Pantone) or will have areas that are embossed/varnished etc. These are generally created as vector artworks in Freehand/Illustrator/Corel Draw (ew!) so the perfect format is an editable PDF. This contains all of the original Illustrator information and can be viewed by both mac and pc users.
(Vector artworks can be scaled up and down without any breaking up as they are based on specific mathematics which define the shapes and relative distances etc.)
You only begin to run into trouble when your logo contains halftone images (JPEG, BMP, TIFF) etc as these are resolution specific and cannot be scaled up over 150-200%.
If your logo does contain a mixture of vector and halftone imagery then you need to ensure that you send your linked file as well as the Illustrator file to your printer. (I know you can embed images, but it does make for larger files.)
Fonts are best converted to paths/outlined.
Just need to let the printers my clients use that they can open a PDF from Illustrator and not insist on .ai files!!
I work at a printers, I know I can open a PDF in Illustrator - if it was created by illustrator. Only then would I do so as all sorts of wrong things can happen if the file was not originally created in Illustrator.
The format we prefer to receive is an eps file for logos.