Matt, I'd definitely recommend you purchase one of the flexible hose assemblies instead of the rigid tube grease gun nozzle. Most grease guns come with the rigid tube about 8" long with the nozzle screwed onto the end. Especially when greasing your deck spindles, you may not be able to get the nozzle onto the zerk squarely and grease will leak out around the adapter. With the hose, you can find a position to hold the nozzle squarely to the zerk and not have blowout type leakage.
Also, don't forget the zerk in the center of the front axle (the axle up/down pivot point). It's a bit of a pain to get to, but you want to make sure that bushing doesn't wear out. All the other zerks are pretty straight forward. The deck spindle zerks will have a cutout in the plastic shields to allow the grease gun nozzle onto the zerk, but you might have to feel around the spindle and remove any debris that could be in the way. This is from the top of the deck. There's no greasing required from the bottom of the deck.