I drink 2-3 cups (DH calls them gallon mugs cause they are the bigger cups) of coffee a day. Just make sure to drink enough water to compensate. The first 4-6 months no coffee after 3pm for me because DS2 would be up all night. Now that he's over 11 months I can pretty much drink whenever I want and he's fine.
There's no reason to avoid caffeine while breastfeeding unless you notice it causes irritability and restlessness in your baby. I was able to drink my coffee just as I did before and during pregnancy with no issues.