Yellow poplar is one of the most common secondary woods in woodworking. Mainly because it is cheap and plentyful but also because it works relativelly easily for a hardwood but is still harder than say pine which is also comonly used as a secondary wood. poplar works good on the face grain and hand planes beautifully. Since it is a sonfter wood you have to watch out for the end grain though. Also another thing to watch out for is the quality of it. Since it is very much a utility wood it is cut from almost anywhere they can get it from and therefore there is a lot of cathedral grain and i find a lot of the poplar around here isnt as dry as the more expensive woods and tends to have a lot of movement especially when cutting it up into smaller strips. Poplar is probably in my opinion the best wood for beginners to work with and with some special finishing techniques you can get a very nice finish on it. colors range from white to heart streaks of green or brown.