Is it allowed? Should I notify/ask the admins here first?
I have been looking into this. Basically you would not be able to use the arduino name as your site name or for any projects/products becuase that is a trademark. Regarding using it, you can use most images (many are under creatuve commons sharealike licenses) but it is always a good idea to credit the person who's image it is. The name arduino can be used anywhere as long as you are not implying that it is anything to do with you and you credit/add a link to arduino.cc on the page somewhere.
The best thing to do basically is to use them but credit the authors and ink to arduino.cc. You cannot use the arduino name for any of your own stuff though...
Mowcius
Indeed. That's why Arduino clones are "Arduino compatible" and things "Work with Arduino", instead of simply being "Arduino [product name]".
Alright. So then is it alright that I have a link to arduino.cc on every page (its on the side bar)? Does this account for any time I use the term?
And what about spinoffs? Ardu[insert wittty suffix here]
You don't need an arduino link on every page... You just cannot use it for your own products/services etc. As long as it is obvious who the term arduino belongs to then you should be fine. It's like microsoft - people don't link to the microsoft page ever time they mention it but everyone knows who owns that trademark and nobody tries to use it for their own gain or they get sued! 
It can be a complicated issue though. If there is something wrong then the worst the arduino team is going to do is ask you to change something...
Spinoffs are fine cos they are not trademarked although if it is too close to arduino (arduinoo or something then it might breach copyright). Things like freeduino etc are fine
Mowcius
Alright thanks. The link thing isn't blatant - its in a sidebar section labeled "useful links" so if anything, I doesn't seem out of place at all.
Well if you are only quoting the arduino name (not for a product etc) then you don't need a link. I'm sure you want to promote the use of arduino anyway 
Mowcius
Yea, that was the intended point.
Spinoffs are fine cos they are not trademarked although if it is too close to arduino (arduinoo or something then it might breach copyright). Things like freeduino etc are fine
If the Arduino name is a valid trademark then spinoffs would probably not be fine (at least in U.S.). They would fall under section 2(d) likelihood of confusion. The name is similar enough and the goods are in the same marketplace. I would think TTAB
would rule in favor of the Arduino.
Arduino, LLC applied for the U.S. ARDUINO trademark put was refused on
6/27/2009. The office action grounds where 2(e)(4) merely a surname and the fact
that no filing basis was specified in the application. If would probably not be
difficult to convince the examining attorney to overturn these issues.
(* jcl *)
I don't want to cause a lawsuit here tho. Can any admins perhaps clarify this situation? What's the usual procedure people go through to name something they make (e.g. an arduino shield)?
There is a FAQ about this at http://arduino.cc/en/Main/FAQ
(* jcl *)
I doubt very much the Arduino team would just sue you before warning or asking you nicely :).
At the very least, you'd get a cease and desist (C&D) letter from them before a lawsuit. ;D