A couple of quick questions on contracting

[poshboyracer]

I'm applying for a few contract roles, having only ever worked as a perm.

I've got an interview today - is there any difference in how to frame yourself in a contract interview vs permanent interview.

Also, how does a contract work with regards to the "employer" binning you? Is it easy for them, and is the notice period a week? Or does it vary from week to week? I ask because one role i have been put forward for has quite a few elements outside my experience - the agent says it's fine (of course they do), and i'm confident i could learn stuff, but i'm not sure that is what a company would be looking for in a contractor and may want to get rid if these elements make up a more significant part of the role than the agent is letting on...

TIA

[poshboyracer]

Great answers, thanks. Will help with my choices a lot.