Translations for TeXmakter?

If what you're asking is how to help with the translation, seeing as texmaker doesn't use launchpad for managing the localization files, you should first download the source code http://www.xm1math.net/texmaker/download.html (the last item on the list) and untar it (right click -> extract) in here you'll find a folder called "locale" with two files (actually a lot of files) one called qt_**.qm and the other one called texmaker_**.qm where ' ** ' is the locale (in your case I believe is 'no').

You won't find the one you're looking for (because as you pointed out it doesn't exist yet), so basically all is left to do now is open one already created and change the name.
For instance 'qt_de.qm' ==TO==> 'qt_no.qm' once you do this, you can start changing the strings; in order to do this, I recommend an open source app called Virtaal (there are a lot of this apps, but this one happen to manage this types of files) to install it in Ubuntu just look for it in the 'Ubuntu software center'

Once you finish this ones, you might want to translate texmaker_**.ts which is located in the source folder; you can also add the Norwegian dictionaries (usually is just copying and pasting OpenOffice.Org dictionaries, this can be done because the licences are compatible).

After all this work you can send this files to the developers: pbrachet[at]xm1math[dot]net

PS: I'm NOT a texmaker developer, just a user, who happen to like helping free software; so you may want to ask them first (so you don't work in vain) just send an email to pbrachet[at]xm1math[dot]net

hope it helps