well you cant actually "change" your pore size, but excess oil and dirt will make them appear bigger. So I would recommend cleansing your face at least once a day followed by some kind of toner to remove residue. But if you are looking for a lotion to apply before makeup like a primer type thing, Clinique has some excellent ones:
I use Aveeno moisturizer, but before you put it on make sure your face is clean, wash your hands before and after touching your face, and rinse with very very cold water which closes pores then put lotion on and don't touch your face anymore
I think your best bet would be to use a pore cleanser when you wash your face, so you can use any moisturizer...(you're trying to keep them from getting clogged, right?)
I don't know that there is a specific lotion for people with big pores. I think any moisturizing face lotion will be alright.
the best one for me personly is clean and clear exfoliating daily wash :)
the link is to cliniques "pores" section on their website FYI