In the USA, Poison Control is a national effort headed (and largely funded) by the Center for Disease Control, or CDC. Perhaps the most visible accomplishment of the program is the "Nationwide, toll-free number for poison control" .
For Poisoning Emergencies Call:
If the victim has collapsed or is not breathing, call 911.
The American Association of Poison Control Centers, or AAPCC is co-funded by the CDC and the Health Resources and Services Administration (HRSA). They set voluntary standards for poison centers and tabulate national poisoning data.  In essence, they provide a conduit of information between the CDC and the poison centers.
Each year the AAPCC publishes information from the Toxic Exposure Surveillance System, or TESS -- The results of poison exposure and poisoning reports to the US poison centers.
Poison centers are centers for the distribution of information on poison. These institutions, spread out around the nation, are typically staffed by nurses, pharmacists, and/or toxicologists. When you call the 1-800-222-1222 number, you are connected to one of these centers, supposedly whichever is closest to you. The old regional poison control center numbers are supposed to still work, but one is urged to learn the new number. 
Poison control centers can accept TTY/TDD calls in order to support the hearing-impaired. TDD calls are accepted on the same number. Also, the poison center system has translators who speak 140 languages. All of these services are, of course, free.
The ASPCA maintains an animal poison control line which costs $45 per incident. You can reach it at 888-4ANI-HELP, or 888-426-4435. They do accept credit cards, so you can buy information on your pet's life by going into debt. You can also get this service on your phone bill via a 900 number: 900-443-0000. This service receives no public funds , hence the significant cost for a service which is available twenty-four hours a day, seven days a week. Followup calls on the 900 line are free; for followups dial 888-299-2973.
These basic first aid tips are provided by the 1-800-222-1222 website . Some enhancement has been provided.
- If the person has collapsed or stopped breathing, call 911 (or your other local emergency number.)
- If the person has swallowed the wrong medicine or too much medicine, call 1-800-222-1222. Do this even if you think you know at what dosage is dangerous.
- If the person has inhaled poison, get them to fresh air immediately, and rinse any affected skin with running water for 15 to 20 minutes. If symptoms worsen, call the number (you know which one.) Some poisons (such as insect poison) can be absorbed through the skin.
- If someone gets poison in their eyes, rinse with running water for 15 to 20 minutes, and call the number.
Things not to do if someone has been poisoned, unless you are an expert:
- Do not attempt to induce vomiting via ipecac syrup. Sometimes this is the wrong thing to do. Most especially do not try to induce vomiting through gagging, such as with a finger or other foreign object.
- Do not give activated charcoal. Sometimes it will bind to things and render them harmless; sometimes it will just make you throw up and that can cause more damage in some cases.
- Do not give someone milk, saltwater, or home remedies like mustard or raw eggs. I have not included milk as a 'home remedy' because it is occasionally the proper treatment, though this may be an injustice. Mustard and raw eggs are completely ineffective, and could quite conceivably exacerbate the problem. Especially raw eggs. Too much salt can kill you, and it doesn't help any more than fresh water, anyway.
- Webpage: Injury Fact Book 2001-2002: Poison Control. CDC, 2002. (http://www.cdc.gov/ncipc/fact_book/21_Poison_Control.htm)
- Website: American Association of Poison Control Centers. (http://www.aapcc.org/)
- Website: Poison Help 1-800-222-1222. American Association of Poison Control Centers. (http://www.1-800-222-1222.info/)
- Website: ASPCA: Animal Poison Control Center. ASPCA (http://www.aspca.org/site/PageServer?pagename=apcc)
Additional note: There is a list of poison control centers around the world at "http://www.aapcc.org/director2.htm". I intend to add it to this WU at a later date. Feel free to do so if you enjoy pain; I hope to get to it soon.