First of all read up on the basics, Kodak have a good tech doc on the basics here:
http://motion.kodak.com/motion/uploadedFiles/US_plugins_acrobat_en_motion_education_sensitometry_workbook.pdf
To work out a films range you need to look at any given film curve, here is one from an Ilford film.
The two points marked are the effective pictorial range and quite massively over what you will need in practice.
Like Roger stated it is the CI or gamma that limits the range of tones recorded; the higher the Gamma (steeper curve) the more narrow the range.
The way to look at these curves is the amount of scene brightness (log exposure) along the bottom (x axis) is translated to density up the side (y axis), low gamma say 0.5 (low slope) will be able to record a wide range of tones, high gamma 0.75 (steep slope) less tones.
In any case this is moot because most long scale films are capable of recording scenes of 128:1 which is the average scene, the whole ISO speed point mandates a low 32:1 SBR which is only 1.3 units along the X (bottom) axis.
Your skill will only really be needed when the SBR exceeds what the film can record over the stated range that's when you'll need to make the curve more shallow buy lowering the speed (EI) and developing to a lower gamma (reduce development time)
In practice people worry too much about dynamic range it has become a 'cause célèbre since the advent of digital used by film proponents to goad digiphiles and make them hand-wring in order to obtain more.
Long scale scenes compressed by correct exposure and processing can if done correctly can look unexciting or betray the wide SBR, or even just look plain flat.
In other words massively wide range of tones taken in bright conditions can look as if they weren't...
Sometimes a scene with heavy shadow and punchy mid tones can look dynamic and more pleasing.
Don't get too hung up on DR...
Sorry I haven't got time to explain properly, read the linked simple primer PDF and all should become clear.
