The following frequency data is directly from the ARRL Considerate Operator’s Frequency Guide. These frequencies are generally recognized for certain modes or activities under normal conditions (all frequencies are in MHz). These are NOT regulations, only guidelines. Occasionally with a high level of amateur radio activity, such as during a period of emergency response, DXpedition or during a contest, there will be stations operating outside these frequency guidelines - you must listen carefully... before even considering any transmission and then act accordingly.
Nothing in the rules recognizes any net’s, group’s or any individual’s right to any set or special privileges with respect to any specific frequency. Section 97.101(b) of the Rules states that "Each station licensee and each control operator must cooperate in selecting transmitting locations and in making the most effective use of the amateur service frequencies. No frequency will be assigned for the exclusive use of any station. No one "owns" any set frequency. However, social manners are implied and so moving away from a net frequency is strongly advised. This is really important during natural emergencies and disaster relief efforts.
It is good practice, and plain good old common sense, for an operator, regardless of mode, to check to see if the frequency is "in use" prior to engaging operation {that is part of the actual regulations, as well}. If you are there first, other operators should make an effort to protect you from interference to the extent possible. Given that 100% interference free operation is an unrealistic expectation in today’s congested bands, some level of interference should be accepted. Try to keep all conversation(s) and content within an acceptable limits (technical and social). It is best to not engage in arguments over frequency usage (just a 'word to the wise'). These develop into "everybody loses" situations quickly at the very best and can lead to a high level of frustration - most probable outcome.
Frequencies {MHz} & Bands Modes/Activities
By Band Wavelength
160 Meters
1.800-2.000 CW
1.800-1.810 Digital Modes
1.810 CW QRP calling frequency
1.843-2.000 SSB, SSTV and other wideband modes
1.910 SSB QRP
1.995-2.000 Experimental
1.999-2.000 Beacons
75/80 Meters
3.500-3.510 CW DX window
3.560 QRP CW calling frequency
3.570-3.600 RTTY/Data
3.585-3.600 Automatically controlled data stations
3.590 RTTY/Data DX
3.790-3.800 DX window
3.845 SSTV
3.885 AM calling frequency
3.985 QRP SSB calling frequency
40 Meters
7.030 QRP CW calling frequency
7.040 RTTY/Data DX
7.070-7.125 RTTY/Data
7.100-7.105 Automatically controlled data stations
7.171 SSTV
7.173 D-SSTV
7.285 QRP SSB calling frequency
7.290 AM calling frequency
30 Meters
10.130-10.140 RTTY/Data
10.140-10.150 Automatically controlled data stations
20 Meters
14.060 QRP CW calling frequency
14.070-14.095 RTTY/Data
14.095-14.0995 Automatically controlled data stations
14.100 IBP/NCDXF Beacons~ DO NOT TRANSMIT HERE!
14.1005-14.112 Automatically controlled data stations
14.230 SSTV
14.233 D-SSTV
14.236 Digital Voice
14.285 QRP SSB calling frequency
14.286 AM calling frequency
14.300 Nets are here pretty much 24/7 - listen first
17 Meters
18.100-18.105 RTTY/Data
18.105-18.110 Automatically controlled data stations
18.110 IBP/NCDXF Beacons~ DO NOT TRANSMIT HERE!
18.162.5 Digital Voice
15 Meters
21.060 QRP CW calling frequency
21.070-21.110 RTTY/Data
21.090-21.100 Automatically controlled data stations
21.150 IBP/NCDXF Beacons~ DO NOT TRANSMIT HERE!
21.340 SSTV
21.385 QRP SSB calling frequency
12 Meters
24.920-24.925 RTTY/Data
24.925-24.930 Automatically controlled data stations
24.930 IBP/NCDXF Beacons~ DO NOT TRANSMIT HERE!
10 Meters
28.060 QRP CW calling frequency
28.070-28.120 RTTY/Data
28.120-28.189 Automatically controlled data stations
28.190-28.225 Beacons
28.200 IBP/NCDXF Beacons~ DO NOT TRANSMIT HERE!
28.385 QRP SSB calling frequency
28.680 SSTV
29.000-29.200 AM
29.300-29.510 Satellite downlinks
29.520-29.580 Repeater inputs
29.600 FM simplex
29.620-29.680 Repeater outputs
W1AW's Bulletins & CW Practice Frequencies:
Listen to W1AW's phone bulletin 0145 UTC on 1.855, 3.990, 14.290, 18.160, 21.390, 28.590, and 50.350 MHz (SSB), as well as on 7.290 MHz (full-carrier, double sideband AM), and on 147.555 MHz (FM simplex). There are CW, Digital transmissions as well. The CW practice transmissions are very popular for those wanting to learn and improve their CW skill sets. See the ARRL's W1AW operating schedule for full details (times, etc.). I have switched my method to practicing CW to the internet, but this not something everyone can currently do.
The 'bulletins' contain current information on various topics and you should have a habit of listening to them often. They will list some frequency usage guidelines based on current issues and demands. Natural disaster efforts are usually quickly posted, allowing you to stay clear of support efforts. Following the current information is always a good plan.