Denpa song English guide:
http://denpa.omaera.org
Wikipedia:
http://en.wikipedia.org/wiki/Denpa_song
Denpa no Sekai Blog:
http://www.denpanosekai.com
http://twitter.com/denpanosekai
Music downloads:
http://www.mediafire.com/RapeTheLolis
http://www.mediafire.com/denpasong
Denpa song bot (new songs every day):
http://twitter.com/dempa_bot
In-detail analysis of denpa aesthetic:
http://altairandvega.wordpress.com/2012/03/21/denpa-bigaku-riron-the-rise-of-the-radio-aesthetic-in-japanese-subculture-in-the-21st-century/
takeshi0406's blog (very informative):
http://sciandeng.blog38.fc2.com/
Denpunk bot:
http://twitter.com/dempunk_bot
Japanese guy who makes denpa and moe songs mixes:
https://soundcloud.com/mossya
moep's blog, he posts buy lists for events like Comiket and M3:
http://moepdemp.blog.fc2.com/