thanks, yes you're right. i also write for free but can't share everything unpaid. do you know anything about sites like tutsplus.com pay authors or not?
You might also want to consider submitting your content to digitalocean or linode, they have great tutorial site.
For self publishing you might want to try Leanpub (https://leanpub.com/)
I also see some great content hosted on gumroad (https://gumroad.com/)