Yes, please do put in a note as to who you are and who your Yorkie is so that your Secret Buddy can thank you for your wonderful gift! A little card or a quick note will do.
You can give as many gifts as you would like, generally, the idea is to have all items packaged into one box for your Secret Buddy if possible. If you are ordering something special and it is delayed, then you may ship multiple boxes. The minimum gift amount is $15 and the maximum is $20, but the maximum is only a "suggested" amount only, and if you want to give more, you may go ahead and do so without penalty. Many YorkieTalkers have been known to be awfully generous in Gift Exchanges.