The keys on the right hand of the accordion are played like you'd play any other keyboard, so if you've ever played the piano (or other keyboard instrument), this part should not pose any particular difficulty and requires little explanation. Note though, that accordion keyboard technique and fingerings sometimes differ from the piano's, because of the angle of the keyboard and because the keys do not control the volume of the instrument. For pianists, another change is that it is harder to see an accordion keyboard, making finding notes and chords harder. (While the accordionist can see the keyboard, she looks down on it from the top of the row of keys.)
The accordion's keys are also somewhat smaller than a piano's, making certain stretches and leaps more convenient. In some way, the technique is closer to that of a harpsichord or an organ, in the sense that all the keys are struck with about the same amount of force regardless of dynamics.
When playing, make sure your elbow does not sag towards the side of your body but is kept up and outwards, so that your arm from the elbow down is more or less parallel with the keyboard. This may seem a bit unusual at first, but in the long run will give you more control and accuracy because the circulation to the extremities of the hand is not impeded.
Make sure your hand is as relaxed as possible while still hitting all the notes correctly - also try not to make much extraneous motion with your fingers. This way, you will tire yourself out as little as possible. Remember there's no need to hit the keys with a lot of force for extra volume like on the piano. On the accordion, to get extra volume, you use the bellows with more pressure or speed.
Like the organ, the keyboard hand has access to register switches which change the sound. The accordionist changes these switches either between songs, or, if a change is needed during a song, in a rest for the keyboard hand. On an accordion, the register switches for the keyboard are on the keyboard side, while the register switches for the buttons are on the button side.
Note: This book does not currently contain learning material for those unfamiliar with the keyboard layout, but you may wish to see relevant sections of the Piano book for instructions in the meantime, which should be similar to the accordion as well.