how did lincoln expand the powers of the presidency? Could someone give me general ideas as to how?

Answer 1

Check this article.

http://www.historycooperative.org/journals/jala/26.2/tap.html

Answer 2

http://blog.oregonlive.com/books/2008/03/book_review_president_lincoln.html

http://www.historycommons.org/entity.jsp?entity=abraham_lincoln

Both of these articles/reviews should give you some ideas to pursue.