Ok, here are a few. Not all have diagrams or step by step instructions, some do. But all are excellent origami websites.
Individuals:
http://orillaqta.blogspot.com/
http://www.anniefolds.com/index.html
http://www.geocities.com/belenga/box/
http://web.mit.edu/chosetec/www/origami/
http://www.cattail.nu/origami.html
http://www.geocities.com/origamiguy1971/main.html
http://www.west.asu.edu/icdeg/clickclack/cc.html
http://www.divulgamat.net/weborriak/Cultura/papiroflexia/cupulasgeodesicas.asp
http://www.ganymeta.org/~darren/origami.php
http://members.aol.com/ukpetd/
http://www.geocities.com/snowflakegame/
http://www.paperfolding.com/diagrams/
http://www.origamitessellations.com/
http://www.artorigami.com/index.htm
http://www.angelfire.com/art/gilad/index.html
http://members.shaw.ca/gtarigan/index.html
http://members.verizon.net/%7Embuckley/tape.html
http://hugo.pereira.free.fr/origami.html
http://www.mat.unb.br/lucero/orig_e.html
http://www.origamihara.com/2005_website_001.htm
http://marckrsh.home.pipeline.com/
http://www.creaselightning.co.uk/
http://sg.pg.photos.yahoo.com/ph/markhor88/my_photos
http://michelturmel.tripod.com/english/index.html
http://members.cox.net/michelesorigami/index.shtml
http://www.geocities.com/mikebr2003/index.htm
http://gregorigami.art.pl/index.php?akcja=home
http://lyno.org/origami/
http://www.nuwen.net/poly.html
http://www.geocities.com/Rachel_Katz/
http://home.tiscali.nl/gerard.paula/origami/knotology.html
http://www.oriland.com/oriversity/basefolds/main.asp
http://www.origami-artist.com/
http://home.comcast.net/~peterfarina/
http://www.nashvillebirthpartners.com/photos/categories.php?cat_id=3
http://pg.photos.yahoo.com/ph/polypolyhedra/album?.dir=/5f66&.src=ph&.tok=ph8C4hDBfDcS1kvG
http://www.raviapte.com/gallery/OrigamiModels
http://www.ulitka.net/origami/index.html
http://home.earthlink.net/~rosa_sanchez/rosa.html
http://www.saadya.net/homepage.php
http://theory.lcs.mit.edu/~edemaine/thok/delian.html
http://www.fishgoth.com/origami/index.html
http://www.eden.rutgers.edu/~suchan/555/final/
http://www.geocities.com/foldingca/swami.html
http://uk.pg.photos.yahoo.com/ph/thiomor/album?.dir=cef5&.src=ph
http://www.merrimack.edu/~thull/
http://www.angelfire.com/sc3/tp_kong/
http://www.bloom4ever.com/howto/howto01.htm
http://www.origami.as/home.html
http://www.pbase.com/apc62/origami
Organizations:
http://www.pajarita.org/index.php
http://www.papercrane.org/
http://www.britishorigami.org.uk/
http://www.origami-cdo.it/indexen.htm
http://www.xs4all.nl/~ploegevd/index.html
http://www.origami.gr.jp/index0.html
http://www.origami-noa.com/index_e.htm
http://www.origamichile.cl/
http://www.papierfalten.de/
http://www.origamiaustria.at/index.php?lang=2
http://www.origami-usa.org/
http://www.origami.art.pl/