One of the biggest assets of the Cartographer's Guild is the huge huge knowledge base the people here collectively have, one outward expression of which is the tutorials forum, as well as general feedback, inspiration from past maps and such. Then there are random links and other tangential knowledge people have regarding mapping.

Even a person completely new to mapping and the programs used can come here and make use of all of that if they wish, and produce wonderful looking maps.

Also I like the friendly atmosphere. I haven't encountered any vitriol on this forum. And even if someone's skill level at mapping is at an early stage, no one is going to say "it sucks", they will simply tell you how to make it better.