Hi,
If your new to PC's / technology in general, I would suggest you start getting used to the concept of input -> output
1 – The tape deck is an output device, the line level input on the sound card is the input device. If you have a nice line level output on your tape deck, use that. If not, use the headphone jack. Its going to be either 3.5mm or 6.5mm. Searching the WWW will tell you (or downloading the manual for your deck)
2 – Purchase cable to connect deck -> PC. Tell the recording app (Wp in this case) where to look for the signal (line level input on PC or just mic input)
3 – Record test, see if levels need tweaking.
Your other questions can be solved with 10min’s playing around, promise
Remember, for just about most things you ever would need to do, there’s undoubtedly 100,000+ other people in the world who have tried / asked about it already; searching the WWW will reveal all.
M