AAALAC is the international accreditation governing body for animal welfare. It is one optional accreditation that institutions conducting animal research can pursue. The website gives the program description and application. The website is also a good source for publications and current news.
AALAS is the site for animal training for IACUC members as well as researchers using vertebrate animals.
APHIS is part of the USDA and is involved in overseeing site inspections. They are the regulatory body that administers the Animal Welfare Act which is the basis of all regulations regarding animal welfare. The website has current news as well as links to publications and regulations including the Animal Welfare Act.
OLAW is the governing body of the NIH and provides links to publications regarding the use of animals in NIH funded grants.
The link to the "Guide to the Care and Use of Laboratory Animals" is the publication that all governing bodies utilize to determine animal welfare. As such this is the publication that animal research institution IACUC committees use as their guidance in animal issues.
The National Academies Press is a website where you can download any pertinent publication regarding animal use in research.