Another recommendation that has been wonderfully helpful are the signing time series of videos.
Our nephew used baby sign language and it made his ability to communicate and our ability to understand him a whole lot easier.
The videos have catchy songs that sit in your head all day, but also sit in our little Colton’s head too. He has been able to communicate basic words before he could talk and even now, when we have trouble understanding him he is able to sign.
Sharpteam recommends baby signing time: http://www.signingtime.com
Sharpteam Blog 
Anna used signs a lot, thank goodness, because she was a late talker, and would have been frustrated otherwise. I remember at her 18mo. checkup, her ped. asked if she spoke the usual 20 or so words. At that time, the only actual words she had were Mama and Dada, but between animal sounds and signs, she was way over 20. We decided that communication was what was important, not the mode of communication, and sure enough, by 22mos, she was talking in full sentences and could recite the whole alphabet song. Her communication skills happened all at once, and I’m sure her history of signing prepared her. I’m now teaching Jase (7mos). Obviously at this age he isn’t signing on his own yet, but he seems to understand – when I say “night night”, he puts his head to his shoulder. It’s a start! A little more hand motion control will help in the coming months.