During monsoon, it totally depends on your travel days. If weather is good during those days, it become very pleasant. Else you will feel lots of humidity making it very sweaty. You will not be able to travel to dudhsagar, if you are thinking to go there as it gets closed during monsoon. Few things will be closed in Goa too, but you will not be missing much. The self drive vehicle will easily available and at a cheaper price.
Are you looking for the resort in South or north goa?