Re your own name/logo: None of them are trademarked until you file them with the patents office and pay the $$$$ to a patent attorney to get it done (around $5K+ where I live).
In common law, your business name and logo may be copyright already. This part is complicated. If you haven't run the business/used the logo for long, they're probably not and anyone can grab and use them. The onus would then be on you to show it was your own work, and the work you've done is actually 'copywritable' = $$$$, complicated and basically not worth it unless you've got or are planning to create a medium sized/largish business. Copyright is very difficult to enforce unless you're a big company and/or have lots of $$$ to spend on lawyers. But remember, copyright only has any real meaning when someone copies you, and you can prove it damaged your business. Having your business logo/name already trademarked is a big help in enforcing a copyright.
For a half-arsed, hokey or new little website outfit, I wouldn't bother. Wait till it's bigger and you can afford to spend the cash to get it trademarked.
Felgall is pretty much wrong on all points. The main one though is :
"A company name is protected because it is a company name"
It's only protected from someone else creating a company in the exact name with whoever the government department that registers names is ie. the word 'protection' here is pretty pointless. It has absolutely zip to do with copyright or trademark, or enforcing either. Like I said, a trademark doesn't exist until you go through the process of registering it with a patents office and copyright is something different again.