how to save a fingerprint from the reader to sql server c# code 2010 ??

hello everyone

i'll work soon on a program that should take the finger print from a reader and save it in sql server to

determine employees's presence and leaving>

i searched alot but still confused from where i shoud start?

my questions are:

1- Is the written code differ from one reader to another? or any code apply to all readers?

2- I knew that i should take the image and save it in varbinary in sql server, but how i shall take it?

3- Libraries i should use in visual studio 2010 and c#?

4- should i write license with a definite number of fingerprints save?

5- when i try to approve an employee pressece (by taking his fingerprint), shall i go directly to his id in SQL server and compare his fingerprint stored with the new one entered, OR i Should take the fingerPrint and search for it? what is better and more professional?

Thanks in advance for every one wants to help me