20 Month Old Son Sleeping Problems

There's lots of advise you can do and try but NONE of it will work unless you are consistent and believe in it. If it's something you do not agree with (Ferber, cry it out, whatever..) don't do it. But whatever you do, you NEED to be consistent!!!
With both my kids, I followed Gracy hog's Secret if the Baby Whispere. She halso has a Toddler Whisperer but I have not read it. She talks about setting up a strong routine and goes through steps on how to put baby to sleep on their own. It's very much like what Super Nanny does, if you ar e familiar.

Good luck with whatever you chose, but remember to be consistent!

There are no easy answers. However, I recommend this book (solve your child's sleep problems, by dr. Ferber). I have consulted this book for both of my kids sleeping issues and it has been a lifesaver. If you are willing to read and consistently apply the strategies mentioned in the book, you should see relatively quick results, provided you are addressing the root of the issue. I have also recommend this book to many of my friends in similar situations. Good luck, stick with it and it will work...it made all the difference for us and I wish I would have done it sooner!

One more note, per the comment about dr Ferber below- i agree with Stephanie A about not wanting your child to go through the "Cry it out" method, that is more like cruel and unusual punishment! BUT his method is actually teaching them that they don't need dependencies to help them fall asleep. They just need you to show them how to fall asleep on their own. So if you do read this book, keep an open mind and decide if these strategies are something you are comfortable trying, and of course consistency is the key!

I am going through the same thing with both a 3&4 ur old. All I can say is "tough love". You can do it
You can NOT give him milk before bedtime or to take to bed though. I WILL cause tooth decay. Water or very watered down juice only

It will be hard to train him to self-soothe and sleep on his own because the optimum time is around 5 to 6 months or so, and you've gone on much longer with him, so Stephanie A has it right, you will need to be consistent.

I've given you a link to help you to help him to self-soothe to sleep which goes into the basics: a bedtime routine which helps him recognize time-to-sleep signals and physically helps his body to get ready for sleep, a dim nightlight, a lovie like a stuffed animal, etc.
http://www.baby-sleep-advice.com/self-soothing.html

Here's a link on various Sleep Training Methods for you to look at:
http://www.baby-sleep-advice.com/sleep-method.html

And here's a link to common Toddler sleeping problems and solutions:
http://www.baby-sleep-advice.com/toddler-sleep-problems.html

Find what works best for you and stick to it ~ I wish you the best!