Robin2:
First, the OP is proposing to use "arudino" which is completely different.
Second, I suspect it is a matter for the relevant domain-name registry to decide whether a particular name can be issued. If the Arduino folks have not already reserved it then that's their problem.
...R
I saw that, but figured it was a typo, since the OP said the site would contain their "own Arudino projects".
Of course if the name is available the registry would issue it, it's not their business to decide copyright issues. Afterall wasn't there a pretty big (and expensive) lawsuit to protect the ownership of the name Arduino? This isn't to say that Arduino LLC would sue a "little guy" just trying to promote the brand, but as they publish their copyright and how to use it (on the page I referenced) they certainly could. I would expect, at least a sternly worded take-down notice.
Robin2:
I can understand someone being frightened off by the possibility of legal action from someone with much deeper pockets.
However the proper way to get an answer to your questions about the use of the Arduino word is to seek the advice of a competent lawyer in the country where you plan to base your business.
It would be interesting to know what law in what jurisdiction entitles the Arduino folk to make the statements in the link in Reply #1
...R
I think the relevant law would be the copyright law in the OP's country (in Canada it would be the Copyright Law of Canada, in the US the Copyright Act of 1976 - those are the only two jurisdictions I know anything about.) It is possible, even likely that the work "Arduino" has been registered in that country, or even if not, and the country is a signatory of the Berne convention, then there would be legal authority to protect the name.
But as you and Bob have pointed out, there have been numerous examples of the use of Arduino in non-official websites, companies and other groups. The page I referenced suggested another legal way to use it though: to ask for permission from LLC. They may indeed grant permission, in return for a statement of non-affiliation or some such.