You need a gear inch calculator. As you will read elsewhere Sheldon is your friend http://www.sheldonbrown.com/gears/
As noted upthread a move from 42->48 ring is a big one. There is a favourite gear ratio thread you can use the search to find on here where people discuss what they are running.
@pharoahsanders started
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You need a gear inch calculator. As you will read elsewhere Sheldon is your friend
http://www.sheldonbrown.com/gears/
As noted upthread a move from 42->48 ring is a big one. There is a favourite gear ratio thread you can use the search to find on here where people discuss what they are running.