On this forum on fictionAlley you can ask for Beta readers.

Fanfiction archives where you can archive your stories once the FQF is over.

Harry/Weasley Slash Archive

FanfictionNet

AdultFanfictionNet

Inkstained Fingers

Restricted Section

Writers Recources

TheHarry Potter Lexicon

Other Slash Harry Potter FQFs

For more FQF we point you to the Fuh-Q-Fest Registry. Despite being a multifandom FQF registry you won't have a hard time finding what you are searching for.