All good advice from everyone but the things that Bill G stated are correct. You must get the dog to listen to you at home. I just went through and still refreshing my 21 month old setter the basic commands. I use a whistle for him to come to me at home and in the field. Also I use the word "no" when doing someting wrong but I don't use the word "whoa" because they are close in sound.
I believe the basics I would teach would be sit, stay, here, heel,no and you could use down. Make it fun and only do it for a short period of time, you will be amazed on how fast they learn. Now is also a good age for an e-collar. There are quite a few good ones out there. I like the Sportdog 1850. Comes with a beeper that you can use with the e-collar or by itself.
Good luck and keep us posted on your results.
