From how you have asked your question about being specific to vb.net it seems like you are not too comfortable with converting c# code to vb.net equivalent(sorry if my assumption is wrong). In that case this will be a difficult task for you because this is not a simple requirement unfortunately. However, please try them out and post here if you get stuck.
Versatile WebCam C# library
Also, if you are willing to see through the learning curve with silverlight then this
] should be much easier.
[Please accept/up-vote answers or solutions that work for you to encourage others]