I recently signed up to SmugMug because I get very good review from folks from this forum. Same idea, I want to put my pictures on the website for my family & friends to pick which pictures they would like to print.
The cost of their prints price is very reasonable & print quality is awesome. I checked the cost on Target, they uses the Kodak kiosk which will print good pictures but prices wise, is a more expensive for for 5"x7" (Target is ~$1.50 & SmuugMug is 0.75~). Both places, prices are comparable for 4"x6". I didn't do research for other prints size. Quality wise (for matte, glossy & glossy B&W), I test printed at both location, IMHO, SmugMug is really awesome if Target is good.
However you do have to pay annual fees for SmugMug.
I am not a pro but I do takes wedding/kid/family portrait pictures for the past years & I am really tired of having to burn DVDs & send them to my clients.
What made me switch to SmugMug is there is limit of 500M per month when downloading pictures to flickr (free account). This month, I accidentally downloaded high resolution files & quickly hit the limit. Was a chores for me to budget the downloading capacity per month for the past few months until I finally subscribed to SmugMug. Again, this is just my opinion.