For Schengen visa information, contact the site http://www.schengenvisainfo.com/estonia-visa/.
When in Tallinn, you can use public transportation - bus, tram, tolleybus - or enjoy walking though the beautiful medieval Old Town. For public transportation maps, timetables, ticket information, see here.
Single fare from the bus/tram/trolleybus driver - 1.60 EUR
However, it is advisable to buy a reloadable Tallinn "Green Card" for 2 EUR, without the need to personalise it. You can either load money or e-tickets to it (over the Internet or at the R-kiosks). Once you return the card, the 2 EUR will be refunded to you.
With one Card a maximum of 6 tickets (persons) can be validated at a time.
More information about the card and how to use it can be found here.
When using the Card, the fare prices will be as follows:
1-hour ticket - 1.10 EUR
1-day e-ticket - 3 EUR
3-day e-ticket - 5 EUR
5-day e-ticket - 6 EUR