I am looking for high quality icon sets / resources. Which one do you use or recommend?
My favorite set is Batch: http://adamwhitcroft.com/batch/
Wow, never saw this set. Love his post on why he went "free".
I bought like 4 of the Glyphish sets... http://www.glyphish.com.
If you're designing iOS, you'll probably notice that his older, iO6ish icons have been used in a TON of apps. I find them to be great to quickly mock up something (mobile or not) because they "feel" consistent... an icon I may use for one element isn't going to look weird compared to an icon used for another.
I've gone back later and replaced or modified things as needed, but to get something out quick and clean for review (and even live), they are great.
http://thenounproject.com every day :)
flaticons are pretty great and come with some cool tools
Pictos, by Drew Wilson.
While not the most beautiful, Font Awesome has everything. I usually end up replacing the icons I use with custom glyphs, but it speeds up the sketching and mockup phase.
I tend to start with pika, gizmo, or symbolicons icon fonts. Working with icon fonts at the start really speeds up the process for me. You can find them here: http://symbolset.com/
Thanks, looks good!