Hi, you can use CD-R, or DVD-R if you just want to backup photies.
I would use CD-R as they are cheaper and there are many brands avaliable.
You can also use CD-RW, which means that you can write to the disc more than once.
If you buy them on a 'spindle' you might want to think about storage, in which case you can buy separate cd / dvd cases/ sleeves etc.
I usually get a good brand of DVD-R from Morissons - 'Maxell' in packs of five in cases for £6.99 + get one pack free, again there are many brands / outlets about.