cbrace,
I have just joined this forum so was not able to put earlier some advices from my point of view. But I believe that is not to late you may benefit this hints.
Regarding your stay in Kraków - it`s a wide known city so many English travel guides exists. You will be able to buy such guide anywhere in Kraków (airport, hotel, newsstands). Must have to see is of course Main Market Square (Rynek Główny) and Wawel Castle.
Other pleases that are worth to see in my opinion are:
Salt mine in Wieliczka, a small city about 10 km from Kraków. You can get knowledge about this mine from the following website:
http://www.kopalnia.pl/ . I highly recommend to visit this mine, it is on the UNESCO`s World Cultural and Natural Heritage List.
Sanctuary in Kalwaria Zebrzydowaska:
http://www.kalwaria.eu/. This city is about 30 km from Kraków. It's also on UNESCO list. I also highly recommend to visit this sanctuary and go through the whole calvary that was build in 17th century with inspiration coming from the calvary in Jerusalem.
Zakopane - this city lies in the southern part of the Podhale region at the foot of the Tatra Mountains. Ca 100 km from Kraków. Very intresting city with a rich regionale folklore. Beeing in Zakopane I would recommend an excursion to Morskie Oko lake. Chochołowska and Kościeliska valleys are also very popular destination for a hike.
Auschwitz concentration camp in Oświęcim (ca 50 km from Kraków).
http://www.auschwitz.org.pl/. Our memento from 2nd world word. This excursion is not for fun or relax. You have to decide whether you want to visit this camp.
Being in Sanok, I would recommend to visit Rymanów Zdrój. A small village and very popular health resort with spa.
Regarding a wedding gift, simply I recommend to ask them about their preferences. Cash or souvenir ? What type of souvenir ? It`s widely used in Poland and quite natural.
Please take into account that a small airport is also in Rzeszów. This city is much closer to Sank than Kraków.
Enjoy your stay in Poland !