copying data form one table to another

   
I would like to know how to copy data from one table to another.
I would like to checked several rows in one table and copy those rows to a new table.

I would also like to know how to copy data to the same table if one column changes.
for example if I have a student table with student data during semester 1 when its semester 2
I would like to copy some of that same data for semester2.

I am new to visual studio 2010  and I am using asp.net
...