Sing songs. Just sing them song to start with!!! To start with, just get the basic chord progression whilst singing. Then focus on getting the actually rhytym. It's a bit of a slow process, but as time goes on it gets quicker and quicker.
My main probably was until quite recently I couldn't sing, now I need to practise. Since you can sing, it's just a case of taking the time to get it all nailed.
I know it's really really plain to see, but sometimes you just need someone to point it out to you!!!
Good luck, let us know how it goes. Hope I helped some.
Don't worry too much about me, ignore me long enough and I'll go away.
