C#.net Desktop Application Printer Setting ConnectionString

Question

hi all,
i am beginner developer in c#.net
i develop a software which will run on medical store.
so i want to print the customer sale invoice, can someone please provide code to attach printer in my C# code so i can print the bill from my client PC and printer.please provide dummy invoice so i can change it to with my information and style.
also when i will deploy this software what is the connection string to attach database file so that my client can run software. i use sql server r2 2008.
Looking forward to get reply and solution soon. 
thanks
best,
zaif