What am I doing wrong in posting

Hi

I have just set up my blog at:

http://crazyaboutwesties.com/westieblog/

However when I started using the editor in “Write Post”, it just keeps changing the format of the text, it would not accept the enter key and other text kept moving up when I hadn’t done anything.

Hope I have explained this correctly. Can you tell me how I can correct this for fuure posts.

Look forward to your valued reply

Jeff