Here are some of my preferences:
- Discussion of using Common Lisp. I like to read about Common Lisp ideas and progress on Common Lisp projects, even if they're not things I'll personally use. I don't mind reading someone who is using Common Lisp while learning it, but I don't want to add blogs that are mostly about using Scheme or Erlang or Emacs Lisp or the OLPC, no matter how Lispy those technologies are on some philosophical level. Some people write about many topics, but categorize things so it's easy for Planet Lisp to select Lisp-related posts. Other people don't categorize, but mostly write about Lisp anyway. People that don't categorize and write only sparingly about Common Lisp are not likely to be syndicated.
- Personal. I like things that are written by a human being for discussion with other human beings. This excludes things like press releases, software announcements that read like big changelogs, conference announcements, that sort of thing. For example, I'd rather see someone on Planet Lisp write "FooCL 3.53 just came out, and it has some things I've been looking forward to for a while..." than simply adding a feed of FooCL release announcements. LispJobs and the CDR blog are a few current exceptions to this preference on Planet Lisp.
- Self-aware. Not necessarily clueful; everyone starts from zero. I don't mind a lack of clue about Common Lisp as long as there's a clue about where you stand in that respect. Some Lisp-related novice blogs remind me of a teacher trying to lead a class by reading a few pages ahead in the textbook without really knowing the material. I'd rather read a novice blog that reminded me of a student's notebook. False starts and dead ends are part of learning, and I like to think that more experienced Planet Lisp readers will help people out in these cases.
I'm sometimes asked "I'd like to start a blog about Lisp, will you add it to Planet Lisp?" Start a blog: yes! Add to Planet Lisp: maybe! I love to see new Lisp blogs, even if they don't always seem suitable for Planet Lisp. People like all kinds of different things, and what I prefer for Planet Lisp won't be the right thing for everyone. If I don't add your blog to Planet Lisp, I will try to at least mention it so other people can find it.