I will have an internship in Czech Republic. I heard that with ISIC, I will have some discounts in Transports Food / Clothes / Rental... Can you please give me some more details?
Aside from what's listed on the official ISIC site, you can usually get a 50% discount at most Czech museums and exhibitions. Some student parties might also have free entry for those with a valid ISIC card. And some bus companies have a small discount for those with an ISIC. Nothing related to accommodation or public transport, though, as that usually requires being a local student.
So the answer is: bring it, but don't count on getting much value out of it.