Regulations

USDA-APHIS Animal Care; this site has many links with USDA-related information including a page of information covering the Animal Welfare Act, its history (pdf), and a page of welfare-related links.
The Guide for the Care and Use of Laboratory Animals (2011); this site includes an unabridged version of the chapters of the "Guide."
The Office of Laboratory Animal Welfare (OLAW, formally OPRR- the Office for Protection from Research Risks' Division of Animal Welfare) at the National Institute of Health.
The document providing legally appropriate euthanasia methods is “AVMA Guidelines for the Euthanasia of Animals: 2013 Edition” published online by the American Veterinary Medical Association. This document is referred to specifically by the Code of Federal Regulations and by all of the major policy guidelines concerning animal welfare in the US.

Recommendations from Professional Societies

The American Society of Mammalogist's (2011) Guidelines for the Capture, Handling and Care of Mammals Used in Research.
The Ornithological Council's Guidelines (2010) to the Use of Wild Birds in Research (web). Select this link to download a pdf version.
Recommendations for the Care of Amphibians and Reptiles in Academic Institutions (1992) from National Academic Press. This is an excellent on-line resource for animal handlers working with herps in captivity.
Guidelines for Use of Live Amphibians and Reptiles in Field Research (pdf) (2004) Second Edition, Revised by the Herpetological Animal Care and Use Committee (HACC) of the American Society of Ichthyologists and Herpetologists.
Guidelines for the Use of Fishes in Field Research (pdf) (2014) The American Fisheries Society, American Institute of Fisheries Research Biologists
American Society of Ichthyologists and Herpetologists
American Physiological Society Policy Statements On Animals in Research and Education
Occupational Health and Safety in the Care and Use of Research Animals (1997). From the National Research Council, this reference contains information concerning occupational hazards associated with working with animals.

Bird, S. J. 2001. The Ethics Of Using Animals in Research.
Bishop, L. J. and A. L. Nolan. 2001. Animals in Research and Education: Ethical Issues. Kennedy Institute of Ethics 11.1: 91-112.
Friend, M. and J. C. Franson (editors). 1999. Ch. 5. Euthanasia. In Field Manuel of Wildlife Diseases. USDI, USGS, Madison, WI. 49-51.
Friend, M. and J. C. Franson (editors). 1999. Ch. 6. Guidelines for proper care and use of wildlife in field research. In Field Manuel of Wildlife Diseases. USDI, USGS, Madison, WI. 49-51.
NIH.2002. Methods and Welfare Considerations in Behavioral Research with Animals. NIH Publication No. 02-5083.
Williams, B. 1999. Wildlife research and the IACUC. In Information Resources of Institutional Animal Care and Use Committees 1985-1999. T. Allen, editor. USDA. Animal Welfare Information Center, Beltsville. 409-416.