Subcatchment parameter estimation in Runoff

I am new to SWMM. There must be a compilation somewhere of the characteristics of subcatchments and the values of WCON that were found to work well for those subcatchments (ie. the computed matched the observed inlet hydrographs). Since A, W (as A/L), and S are basically imposed, Manning's n is left, which then must be estimated based on experience/prior-knowledge in a design situation. Thanks.

Here's how I've told newcomers to start (since the basis for a concept of subcatchment width in real catchments is elusive):

1. for each and every subcatchment, select what you consider for your design problem to be the dominant characteristic surface.
2. estimate its length of travel, mean slope and rough roughness based on a Manning's equation view of hydraulics
3. divide the subcatchment area by this length to get the characteristic width.
4. use the same system consistently for all subcatchments down to your streamflow gage
5. enter the data as the expected values of the parameters
6. calibrate the time response aspect by altering widths of all upstream subcatchments by a constant fraction.
7. hold thumbs