From a type designer or user point of view?

I believe most people (incl. some designers) use Font Squirrel for a reason. Nevertheless answers to your other questions depend on your intended usage (as a type designer, or user/buyer)?

Thanks lars - I ask as a type designer.

I should have mentioned that the fonts I wish to convert areArabic. Unfortunately Font Squirrell only works for Latin fonts.

Try fontprep

Thank you abattis. FontPrep from fontprep.com is nicely designed and creates a neat folder with all the css, svg and html files necessary with just one click.
At first nothing worked until I added encoding declaration to the html

A test page displayed my chosen font correctly in both Arabic and Latin in:
Chrome (Win7 and OSX) , Safari (OSX)
It did not display my font, only a generic one in:
The latest Firefox (Win7 and OSX), IE 11 (Win7)
The svg file did not display anything in Illustrator - what is its function in a webfont?

Any help with this will be appreciated.

Have you considered webfont services like FontDeck or TypeKit? These people have got a whole team working just to serve webfonts. Or you have special requirements (nonlatin script etc.) that can't be met by current webfont service providers?

Thank you Grubstreet both services you mentioned are very interesting. I was wondering whether there is a technical guide about how to convert my Arabic-Latin fonts to woff or whatever else is necessary to make them available for use on a customer's website. FontPrep did all that automatically, and it worked - except in Firefox!!

I now found out why it did not work in Firefox: I had set FF Preferences to display another font. In the Mac it is / Content / Advanced /Arabic After checking the box "Allow pages to choose their own fonts instead of my selections above." it works fine.