Try sfdoc -k <keyword>. For example,

bash$ sfdoc -k velocity
sfexgr: Exact group velocity in VTI media
sfchebvc: Post-stack 2-D velocity continuation by Chebyshev-tau method.
sfagmig: Angle-gather constant-velocity time migration.
sffourvc2: Velocity continuation with semblance computation.
sfdix: Convert RMS to interval velocity using LS and shaping regularization.
sfconstfdmig2: 2-D implicit finite-difference migration in constant velocity.
sfpwdix: Convert RMS to interval velocity using LS and plane-wave construction.
sfdixshape: Convert RMS to interval velocity using LS and shaping regularization.
sfpveltran: Slope-based velocity transform.
sfvelcon: Post-stack velocity continuation by implicit finite differences
sfvscan: Velocity analysis.
sfvelmod: Velocity transform.
sfpreconstkirch: Prestack Kirchhoff modeling/migration in constant velocity.
sfunif2: Generate 2-D layered velocity model from specified interfaces.
sfunif3: Generate 3-D layered velocity model from specified interfaces.
sffourvc: Velocity continuation.
sfimospray: Inversion of constant-velocity nearest-neighbor inverse NMO.
sfvelcon3: 3-D finite-difference velocity continuation on a helix 

If some program description attracts your attention, run the program without arguments for a self-doc, then follow examples in the USED IN section to observe how it was used. Alternatively, use the web interface.
“sfdoc -k .” produces a full list of all programs.

In the absence of a specialized plotting program, this is just a matter of interpolating from polar to Cartesian coordinates. See an example in book/rsf/rsf/radial.

This may not be the most elegant solution but you can try using parameter files. Here is an example:

1. Create some data.
   Flow('data',None,'spike n1=100 | bandpass fhi=40')

2. Generate a parameter file from it.
   Flow('mag.par','data',"attr want=max | sed 's/value = /mag=/' ")

3. Use the parameter file in processing.
   Flow('test','mag.par','spike n1=100 par=$SOURCE',stdin=0)

Plot(‘myfile’,’plot command’) is a short notation for Plot(‘myfile’,myfile’,’plot command’). Both will create myfile.vpl from myfile.rsf. The short notation saves some typing.

sfdots cannot handle irregular data at the moment. However, you can plot regular data with holes. See an example in rsf/rsf/sfdots.

Try sfstolt and sfprestolt.
Some impulse response examples are in sep/forwd and gti/stolt/impls.

I would like to contribute my program to RSF. What do I do?
Update: Please see Adding new programs to madagascar.

Is it possible to plot irregularly sampled seismic data in RSF?
Yes, if you use sfwiggle. See RSF/book/rsf/rsf/wiggle for an example.

Why does not RSF store a complete file history in the header (as SEPlib does)?

Not keeping complete file histories in header files was a design decision. The reasoning is that processing histories belong in other places (namely, the SConstruct files), and one should not rely on the header information for figuring out how the file was processed. A technical detail is that, since history parameters are stored in a hash table, they are outputed in random order. Please let us know if you can think of compelling reasons for changing this behavior.

Update: the behavior has changed following the suggestion from James Rickett. File histories are now stored in RSF files.

Is there a place on my own machine where I could point my browser to see the program self-documentation?
Yes, point it to $RSFROOT/doc/index.html. The contents should be identical to those on the selfdoc page.