BBC Bitesize/BBC iplayer
I have discovered that the BBC bitesize website has several levels of notes for Scottish gaelic.
However, if you go through 'all topics', you can see gaelic for various levels of school.
This is clearly geared towards school exams and rather limited but it still has some useful content including web pages in gaelic.
For anyone in the UK with access to the bbc iplayer website, there are some programmes on there in Gaelic. Go to the category 'Scotland' and when you scroll through the available options, several have gaelic titles.