To get to Peterhof, one typically takes a hydrofoil boat from one of several piers in the City Center of Petersburg. We started early in the morning, but, true to Russian form, were forced to declare at exactly what time (and which boat) we would be coming home.
I was on the same hydra boat ride a few times. Don't remember having to tell when we were returning.
Agree with ML. Admittedly my trip was several years ago, but I didn't get asked. That hydrofoil trip was the first time in Russia that I was the "victim" of "you're a foreigner, so you will pay more." It was something like 150 roubles for Russians and 250 for foreigners (or a similar proportion, anyway). I skipped the return trip, and took the bus from outside the main gates. It terminates at Leninskaya Metro - and it's the same price for anybody (a LOT cheaper than the hydrofoil).

However, be warned - there are 33 separate areas within the Palace and grounds, and every single building has their own entry fee and ticket office, so people who don't have unlimited funds have to choose carefully which parts to see. Again, foreigners pay more - it will cost an adult non-Russian 10,350 roubles to visit them all! That's $US 160 - Russian citizens get charged around half that in total. It would be nice to see an "all areas pass" as well, sold at the wharf or the top gate, so that you didn't have to keep queuing at the booths but could just walk straight in. Something like this could surely be sold at a discount as a two-day or three-day pass (like The Hermitage), because nobody would have time to visit everything in one day.
The Upper Garden is the only area that is free all the time, but I see from the Peterhof website that the "Petersburg Card" (tourist pass, which wasn't around when I visited) gives free admission to the Lower Park. From October 12 it has also given free admission to the Grand Palace and Cottage Palace. One downside is that photography within the Palace is now banned - that is a serious loss for tourists.

I managed some amazing indoor shots when I was there.
Peterhof is a paid attraction. I believe that our entire fare for the visit was around $20 USD for the three of us. There is a receiving area that is quite large, having room for probably 12 of the boats we came in on. Upon walking off of the jetty, one gets the idea that you are walking back through history. There is a small channel running from the main building area that is more like a slow moving waterfall. It follows the main walk way and shows some of the thinking that went into building the area.
The Museum of Imperial Yachts is right next to the wharf. Its a good way to whet the appetite for what's at the end of the Grand Cascade.
Directly beneath you are a series of fountains that, for the time they were built, were considered to be the most beautiful in the world.
You're kidding, right? They still are!
Now, earlier I mentioned that we had to declare when we were going home. What they didn't tell us is that the only food that is really available here is through kiosks and it is snack food. Not real food. When N asked a couple of the workers they mentioned a restaurant close to the Grand Palace, but also that people had gotten sick eating there and that it did not serve good food.
Again, I'm going back several years, but the restaurant was (still is?) on the terrace level of the Palace, at the left end as you look at it from the front. I had an absolutely fabulous meal there, and while I wouldn't want to argue with the people to whom you spoke, I find it hard to imagine, with the number of tourists who visit, that they would have let the culinary standards slip to the extent that people were getting ill.
For those visiting Petersburg in the future, Peterhof is a required destination for your trip. But I would recommend spending only a morning or an afternoon there. There is not really too much to do except to walk around. It is a massive complex, three or four areas of visit and you are petered out, so to speak.
I beg to differ, but then I'm a museum-type person. I got there about 11.30, and had to leave when they shut the gates at 5 (it's open much later these days), and still had a heap of things to see.