Learning to sing is pretty much the same as the guitar. Practice, practice and more practice. You did not say whether your just do not like the tone of your voice or whether you are singing off key or hitting occasional bad notes. However you are doing right by recording yourself and listening to the results as you can check where you are going wrong. You could be trying to sing in the wrong key for your voice or in a style that does not suit. Maybe some lessons with a vocal coach is the answer.
Biting the bullet and letting someone else listen to your recordings can sometimes throw light on where you are going wrong. You are better getting help from someone close at hand but I am willing, and I am sure that Russ would too, offer advice if we heard a recording of your singing.
Worst case scenario: There are a few people who are completely tone deaf and never actually hit the note that they think that they are singing, but they are very few and far between. A lot of people say they are tone deaf but in reality they are not prepared to put the effort in to sing correctly.