I need Youtube and Goole API help!

Hi, I want to make an application that will use an email and a password and login to Youtube and post some data . I have found that I can do this using youtube's API so I created my dev account and registered my app. Now I have my client ID, my client secret and my API key ... I have read almost all the documentation available and I have tried a lot of examples (none in vb.net - the platform that I'm using) but I can't login to youtube... I have tried ClientLogin and I managed to obtain the auth key but when I use it to post I get a response that the token is not good so I tried to use oauth2 but I had no success with that also ... I need help!!! Please someone show me some working code for authentication for youtube to get the tokens that I need ... another problem is ... how do I make a POST request using XML as my data that has to be posted , I only worked with form content not with xml content but the google api requests are sent in xml format...
Thank You!
PS - this is a legit question and do not break any rules or TOS, google has made this api public (the problem is that they "omitted" to share really usable tutorials and snippets of code ... at least not for .NET, all the examples are very old and don't work anymore) Please do not answer with links to the API doc - I have 20+ tabs open in my browser with that and is almost useless, you can only learn the principles from it ... If you have the knowledge just take a little time and write some code here and explain how it works!