Change the number of particles and radius of particles for the fluid model

Hi,

I have a naive question. How can I change the count of particles and radius of particles for the fluid model, such as the bunny? Also, I noticed that we can change the number of particles for emitter. Will we be able to change the radius of the particles for the emitter? If so, may you please tell me how? 
Many thanks in advance for your help! 