Various sorted (external) links! Heavily inspired by the "links" section from The Sisters Of Mercy's official website.

Reading (sites that contain free digital books)

Bibliomania : This website contains many (classic) books available for FREE in an online text format!
MIT Internet Classics Archive : You can also purchase books in this site.
My Immortal : A fanfiction must-read.

Educational sites worth checking out! (or not)

Fanlore : You think you're fandom lore savvy enough? Me neither. I suggest the "Snapewives" article for starters.

Official band/artist sites

Massive Attack : Looks quite fresh and new!
Pere Ubu : Some pages were last updated in 1997!
The Sisters Of Mercy : This page was inspired by SOM's site's "links" section (as stated above). It looks slightly abandoned. I like it.
They Might Be Giants : Had to include this one! A band with a huge internet presence.

Cool band/artist fansites

Chalkhills : Marvellous XTC fansite! Contains (almost) everything XTC related, including solo projects.
Led Zeppelin Slash : HUH??? Archived site. Fanfics are sadly lost, I think. Funny picture section is still available.
Rockfic : not exactly a music fansite, but, seriously, check this out. That is, if Wattpad, AO3, Tumblr, LiveJournal weren't enough for you...
Slacken_Ties : Franz Ferdinand LiveJournal community. I highly advise you to read harryheartsme's fanfic. It's insane plzpzlpzlzplz read it. (fun fact: did you know FF kinda encourages bandfics? you read that right! they also had a huge undergrpund fanbase from what I've seen. it's called the "Franzdom" if I'm not mistaken)

Miscellanea

will add stuff here