My friend booked the tickets herself back in December and ticketed time slots were already starting to get sold out. And forget about tickets to the crown, I believe that is a 6 month wait! We had tickets for 11:00 (everything earlier was sold out for the pedistal) for security. I believe tickets were $13 each.We arrived at exactly 11:00 and the line for security was quite long. There were 3 lines, those with bought same day untimed tickets (longest line), pre-purchased timed tickets and people with New York Pass, which was the fastest line. Actually the line was so fast that I would encourage anyone going to see the Statue of Liberty to look into this pass, it does have many other benefits besides skipping the line so there may be value to anyone who doesn't have a lot of time in New York City but wants to see a lot.
We waited on line for at least an hour to get to security, which is similar to airport secruity, minus the nudoscopes. You had to take off belts, shoes, jackets, etc. I will say that the security was a little inconsistent. Everyone went through metal detectors, and so did all bags, but it seemed like some lines you had to take your shoes off but on others you didn't. Just like at the airport you can get lucky and have a quick moving line, or you can get stuck on the line with all the rookies and it can take a while. This is done inside a temporary type of building that isn't quite big enough to process as many people as they have coming through.
After you go through security you wait for the boat, boats come every 30 minutes and in spite of arriving at 11:00 we did not get on a boat until 12:30. I think this had to do with there not being enough security lines to process people, but also once you go through secruity and you're waiting for the next boat, the area is not big enough and I think it backs up into the security area which stops or slows down the screening. Of course the waiting area that we were in was kinda roomy with no one encouraging us to move towards the front of the area to make more room.
My point? The security process needs some tweaking so plan a lot of time into your day.
The boat only took a few minutes (and wasn't really crowded), but there isn't a ton of seating onboard. But there is a snack bar with food and drink.
At the Statue of Libery you disembark the boat and are free to walk around the island as much as you want. There is a gift shop and a snack bar on the island too. If you want to go into the Statue you will need tickets that allow access. You will also need to go through security screening again, though there was no line here. Inside is a museum and the original torch, you can learn all about the Statue of Liberty, of course if you didn't plan your day well then you wont have much time for this section. Inside you can climb the 192 steps to the pedistal. I'll be honest, I'm not sure it was worth the work. You get a nicer view of New York City, but a terrible view of lady liberty as you're just looking up her skirt and there's nothing to see there. And the stairs killed both our legs, my legs were spasming, making it hard to walk up or down stairs for a while after. I've climbed to the tops of many things and never had this problem. If you choose to climb to the top of the crown you'll need to climb another 162 steps. 
After we finished on the island we waited online for the ferry which goes on to Ellis Island and then back to New York City. We were short on time so we did not get off at Ellis Island. I have been there in the past and it's nice to see if you have the time, but I don't think it's a must see.
Overall I enjoyed going to see the Statue of Liberty, the Island is well cared for and offers great views of New York City. This is a once (or twice) in a lifetime activity so plan accordingly. Plan to spend a lot of time there, just bring your camera and some money and hope it's a nice day!
