here are some links to articles & interviews for valuable dev advice:

• Interviews Page from World of Level Design
• "Becoming a Level Designer/Environment Artist" Interview
• "Seeing the World as a Level Designer" Tips
• Environment Artist Interview at Platinum Games, featuring an hourly schedule of life as an Env. Artist
• Wholesome Advice from an Environment Artist, via Artstation
• Lv80 Article on Defining the Role of Level Designer

~I will update the link descriptions later

Mapcore is a great website and forum to check out and join!! See their Door Challenge, too~