The best first place to start is WordPress FAQ section. They have answers to many questions and there is a high chance someone has already asked it before.

Below are typical questions we receive from other customers:

1. How can I block unwanted comments?
• You have full control over it. You can either force people to register in order to be able to comment or disable comments for some posts ("Advanced Options" -> "Comments & Pings" -> "Allow Comments").
2. How do I post videos from YouTube?
• While editing your posts, click on yellow A button and copy the address from YouTube.

Short link: http://ofcour.se/~4CH$26