The use of web icons is a very common in current design, as they help to give visual cues to the user. Icons are commonly used in navigation, to accompany text for items such as email links or calendars, and to link to various social networking websites. There are countless websites that have icons for free or purchase, but below are some that offer high-quality, well-designed web icons.
Icon Drawer
Icon Drawer offers several nice sets of web icons for purchase, ranging from $29 to $150, along with some free collections. Several of the free sets are holiday themed, offering some nice options for your personal holiday projects.
Glyphish
Glyphish is a great icon set, designed for mobile apps but also useful for web design. A free option includes 200 icons at small size, and a $25 upgrade gets you 80 more icons, several file formats and a larger size optimized for iPhone 4.
Social Media Icons
This set of over 100 social media icons is designed by Gedy Rivera. Along with the EPS format, the set comes with handy PSD custom shapes, which can be easily imported in Photoshop and used along with the shape tool.
Iconic
Iconic is a free set of 136 web icons in a minimal yet stylized design. The download includes many colors, sizes, and formats, making the set an great choice for various types of projects.
The Noun Project
Stock Websites
More than ever, stock websites are a good stop for finding web icons. Often available in small groups of approximately nine to 16 icons, stock icons are a good choice when you are looking for something specific or that perfect matching set. Try a search for "icons," or a specific type of icon, on most stock sites that offer illustration. Here's a few to start with: