We would say it depends on what you do and if are you planning to invest in the business. The word is the best place to look for people to partner with is LinkedIn.This covers both internet businesses and brick and mortar ones. You can take your time and talk to any and do research on every company before making any decision. As far as we know it is the largest group of strictly business people on the internet and there is no place which has a larger group offline.
This is not the only option there are other platforms or websites where you can meet people who are in brick and mortar and internet businesses. Personally we network on five websites (programs) and deal with many people who have both and online / offline presence.
If your looking for people who are just starting there are several websites which deal with them also. There is also the option of small business think tanks located at colleges and junior colleges throughout the United States as well abroad.