If you've never seen one they are incredible. I don't remember our exact location of viewing but it was at Titusville. We just pulled in where we saw lots of cars and it was a great location.
You can reserve great viewing at KSC but we have been twice and both times the dates were moved due to weather or some other problem so you need to be flexible.
I've been looking into this too...although we won't be there until June 23rd, just in case there might be a delay on the shuttle. If not, there is a rocket launch scheduled for June 30. From what I've read, the best location is along the Indian River in Titusville and that the launch pad can be visible from that area at about 15 miles away. Here's some suggestions.
STS-117 is tentatively scheduled for NO EARLIER THAN (NASA CYA)June 8, but there is only 3 days of contigency time left in "that schedule". If anything else goes wrong they probably won't make it. We are at WDW the 6th through the 13th and may drive down to see it if it's a go.
I was there last year for the July 4 launch and saw it from POR. We'll be there again this year and it really is something everyone should see at least once in their lifetime! It was amazing.
We've twice parked at the Holiday Inn in Titusville for $10. You then have access to motel facilities. Each time the shuttle was rescheduled so it's still on my husbands life goals list!
We were there at Christmas when it returned to KSC. It wasn't planned that way and it wasn't supposed to be landing there, it was supposed to be Edwards Airforce Base, but a change of plan at the last minute and it did. What a great atmosphere, we really enjoyed it, and if we are lucky next time we go, we hope to see a launch. We would try and go to the beach