Whilst not exhaustive, if you are interested in poetry then you may find this list of sites helpful:

• Publishers

Anvil
Arc Publications
Arrowhead Press
Carcanet
Leafe Press
Pighog Press
Shoestring Press
Shearsman
the tall-lighthouse

• Magazines

Horizon Review
Jacket Magazine
London Review of Books
Mimesis Poetry Journal
N+1 Magazine
New Welsh Review
Signals Magazine
Stride Magazine
Succour
Tears in the Fence

• Organistations

Poetry Society
The Poetry Library, Southbank Centre

• Blogs

Gists & Piths
Poets on Fire
Ron Silliman’s Blog

• Events Locations

Bishopsgate Institute
Troubadour
The Poetry Cafe