Plan your work carefully, read as much as you can about different techniques, try to find pictures with completed models, real photos and work-in-progress pictures. They will tell you many interesting and important things.
Also I'd like to recommend you to start using airbrush from the very beginning. This will cost you some extra money and will require some time to learn how to handle it properly but the result will surely worth it. Well, it depends on the scale you prefer but as soon as you're not building 1/1200 ships I'm quite sure that airbrush is the best choice. Surely you will need hand brushes too but in my opinion it's almost impossible to paint large surface by hand without defects.
My friend presented me DKM Tirpitz in 1/350 scale more than a year ago as the birthday present, and I haven't started it yet except some minor spadework. Instead of this I bought quite simple model of Varyag cruiser and started to perfect my techniques with it -- airbrushing, aftermarket etc. It won't be a tragedy if I spoil something -- this model costs 15$ in Russia while Tirpitz costs 100$ and requires additional 200$ for PE sets.