It's good to read these rows
My family shares a lot in common with that interest.
Unfortunately train-transportation is quite underdeveloped in Estonia. Also in extension and also in quality. I'm also from an ex-socialist country, so the quality is not that a big deal for me, but the lines are quite scarcely built, so when we did travelling we did it mostly by bus. It is also faster most of the time because of the connections. I remember clearly it is faster by bus to Tartu, from Tallinn.
"Raudteejaam" or "vaksal" is train-station, however.
A map though: http://et.wikipedia.org/wiki/Pilt:Eston ... etwork.svg
peatus.ee is the site for bus timetables in Estonia. This is an example for Haapsalu: http://www.peatus.ee/#route_search;33183;21945
Bussijaam is bus-station. Always choose the bussijaam-ending one from the list.
I liked Kuressaare pretty much, but I went in the Summer (May). Even then, it takes a half day to get there since there's a ferry you must take, and you cannot make it the way back the same day :/ And in Winter I don't know how much there is to see, you probably see the same thick snow like everywhere. It is a charming Swedish-style seaside town with a big castle of the arcbishop and a nice beach. Personally, I wouldn't recommend it in Winter unless you really like the town and mean to stay there more days. Well, in January, in case it is cold enough, they open the "jäätee" or "ice-road" from the continent to the island. In case the bus uses the road, it might be faster to get there. But it really depends on the weather and the thickness of the ice on the sea.
In Summer we hired bikes and took a bike-tour on one of the islands (Hiiumaa), which was fantastical. That way you really see a lot and experience more of the area. But Winter is so much different there as for transportation :/
I completely understand the car-thing. I would't drive either in that snow, especially.
I've been to Pärnu only three times and all fun I had there was because of the people and/or institution I visited, and though the architecture of the town is nice, and it is the Summer capital and seaside resort of the country, I don't remember any fine historical sites in town. Note the sea is frozen in Winter.
Tartu is a good choice then
If you feel like another trip, then I recommend Narva - besides the castle-thing I described, you can see the "tuhamäed" on the way. I really don't know the English name of those. In Soviet times they did oil-stone mining near Kiviőli (close to Narva) and the remaining material, they didn't need, they simply poured into one big pile. Two actually. So there are two pieces of 110m tall hills on the wide plains that characterize the horizon when you go towards the Russian border, near Kiviőli. (which is a horribly rectangular, grey, Soviet town, even to my Hungarian socialist-realist-used-to eyes.). So it's on the way to Narva. And locals use it for downhill skiing and sleighing in Winter.
If you really want to see another castle, and decide not to go to Kuressaare, then I recommend the one in Haapsalu. Or take that one-hour bus-ride from Tallinn to Rakvere and check the castle-ruins.
There are ancient Estonian earthen-fortresses still visible, but all of them are hardly-accessible by public transport.
Maybe I'm biased, because I lived there, still I can also recommend Viljandi. They have the lossivaremed (castle-ruins) and some cultural life even in Winter too. Some old churches. And the 5km skating-rink in on the lake, all these like 5 minutes walk from city-centre. When you walk down there at the lake, you can see the illuminated castle up there and the forest around the lake, it's a nice view. And can go to some concert to the Ait in the evening.
You can pay by bank-card literally everywhere in the country, in the smallest shops too. Except at the bus and train-stations
(Just the most important ones
I'm not sure about public-transport there, but Jägala-juga is pretty close to Tallinn. It's a tall waterfall that is frozen in Winter and it looks just awesome
One word about castles in-general in Estonia: Estonians never had an aristocracy. There was no Estonian nobility. Feudalism, stone-castles, manor-houses (mőis), and nobility in general were and are all considered the symbol of foreign oppression. When they were occupied by the Germans in the 13th century, free Estonian peasantry became the serfs of the new foreign nobility, deprived from their freedom and their lands. So, after the birth of the independent Estonian state, no-one cared about the renovation of these German or Swedish built and dwelled manor-houses and castles. So, they don't have a lot of historical buildings left, typical elsewhere in Europe.
Instead, Estonians rather cared about the building of their own things: each settlement has a "singing-square" called "lauluväljak" where they gather and hold all their song and dance festivals and other events. Don't miss the biggest one in Tallinn! (It's close to Kadriorg.) Most town-halls, institutions and hotels in the country were built in Northern Bauhaus style in the 1920's. For me it was something new, in Hungary that age is kind of neglectable as for architecture. After the 1990's they started to rebuild the special Estonian swings in parks called "kiik". Even in Winter, you can try and ride one, you'll surely have other adults who stand on it and help swinging,
So, that's why I'm saying always that Estonia is not that interesting for someone who is more into buildings, at least don't expect anything grandiouse. Though, it is more unique and one must have a special interest to enjoy it
And watch out, some things are different in Estonian than in Finnish:
street - tänav
jaam, peatus - station
etc... but ask anything, so we can help
Yeah, and personally I loved their local historica museums. They always have some maquettes of the local earthen-fortresses from old Estonian times and nice folk-costumes and found artefacts from times right after the ice-age.