UK College of Arms Website
This is a great resource on heraldry information and the only organization I know of the actually grants official coats of arms.

The American College of Heraldry
Though this organization does not grant coats of arms they can and do register those arms that people are using or have designed for them. Keep in mind that registering a coat of arms does not mean that arms have been granted by an official heraldic authority.The only organization that grants coats of arms (that I know of) is the UK College of Arms listed above (and they have rules about who can apply for such grants).

The American Heraldry Society
An organization focused on the continued study of heraldry and it's use for American citizens wishing to either research possible arms of ancestors or to obtain their own coats of arms.

The International Association of Amateur Heralds
An Organization dedicated the the study and creation of unique coats of arms and to the continued study of the heraldic arts.

The Royal Heraldry Society of Canada
Focused on the study and creation of Canadian and international coats of arms

The Heraldry Society of Scotland
Focused on the study and creation of Scottish and international coats of arms

The Family History Library
Based in Salt Lake City, Utah, This genealogical repository has records on literally thousands of people and surnames and has genealogists who may be able to help you trace your ancestry. It is an excellent source of genealogy information.

Rootsweb
Another excellent source of genealogical info

anestry.com
This website also contains a ton of great information on genealogy and genealogy research info. Though this site charges a fee to use it's services (as most do these days), the information the site provides is well worth the fee.

Cyndi's List
This is a fantastic website with tons of information. It can be a little daunting but well worth the effort if you are seriously researching your family ancestry.

Simmons Family Webpage
Genealogical information on me and my family. This page is run by my Grandfather and contains some great info.