While Adobe Photoshop has added some support for creating vector illustrations, Adobe Illustrator remains the most powerful software and the industry standard for creating illustrations and vector artwork.
Illustrator can be used to create icons, fonts, posters, logos and more, and because they are vectors, they are scalable without any loss in quality.
The online design community is always releasing new tutorials on how to achieve effects in Illustrator, and here and some of the latest and greatest:
Create a Cylindrical Loading Bar Vector
Graffiti Inspired Line Icons
Create a Plastic Balls Text Effect
Rock and Roll Guitar Poster
Vector Airplane
Easy Way to Make Vector Flowers
Twisted Balloon Text Effect Design
Supersoaker Vector Illustration
Cigarette Text Effect
Cute Deer Illustration