The Pentax digital spotmeter is very easy to use - much simpler than some of the modern light meters. Some of the digital spotmeters have been converted to work even easier with the zone system (basically a sticker with the zones has been attached to the barrel with the exposure rings).
A spotmeter really only makes sense in connection with the zone system so if you're willing to go that route this is a good place to start reading:
Zone System
The easier alternative is bracketing all your exposures and either picking "the best", or sandwiching two or three together and manually masking so that you get more dynamic range, or use the bracketed set to create an HDR image using Photoshop or another application which automate that task.