Hi Niamh,
I'm quite new too so it feels weird being the first to welcome you. Firstly, you must make sure they're always provided with lots of hay as this is their staple diet. It isn't nice for them to eat soiled hay from the bottom of cage though. They can eat most vegetables and although there is no hard and fast rules about how much per day, you should always make sure they are treated to some. I give mine a small amount when I get up and a bowl full when I get in from work. Don't give too many apples as these can cause ulcers. Iceburg lettuce isn't supposed to be great for them in large quantities, and not too much cabbage and dark greens. You can also try them on most fruits like banana with skin and berries. My lot love cucumber, salad, spinach, parsley, brocolli, cauli, and corn on cob. Don't worry too much. If they don't like it they will leave it and just remember not to give it them again. I have two new boys who I tried with leek today. My other ladies love it but the boys were disgusted. Try to stay away from sugary treats like yoghurt drops but you can get healthier treats from the petshops too.
Hope this helps. Good luck with them.
E
