For Tone Out purposes, a tone group typically consists of two tones - Tone A and Tone B. Occasionally there will be a single tone, most commonly referred to as a Long Tone B.
(The single Long Tone B is most often used to reach large clusters of people. Around my area, there is an "All Call Group" which will alert all 500 or so firefighters to things like weather alerts. In taking a quick glance at the chart, I didn't notice any single tone use.)
It can be a little confusing as the word "group" is used in a couple of different contexts.
In your situation, you would find the correct fire department whose tones are those you want your scanner to respond to. For example the Bridgewater Fire Department - you would program 524.8 as Tone A and 582.1 as Tone B, with 154.370 as the frequency.
For your area, it appears that you will always need a Tone A and Tone B.
I noticed on the link you provided, they show some tones as "HM" or "NF". I believe these are Plectron tones. To determine the "number" associated with these, you can visit the link below, which comes from N9JIG in Chicago. For those not listed, I'm sure a Google search will be helpful.
http://api.viglink.com/api/click?fo...//www.carmachicago.com/profiles/ToneChart.pdf
