For good deals on hotel rooms, we recommend Priceline.
There are no big hotels near Brooklyn College, but several subways go there: 2, 5, and Q (see Location). These subways lines go through many parts of Brooklyn and Manhattan, including Downtown Brooklyn, the Financial District, the Union Square area, and the Times Square area. Also, there are many opportunities to transfer from other subway lines to these.
One possible (if slightly unusual?) option that is quite close to Brooklyn College is Midwood Suites. Other slightly unusual options throughout Brooklyn and NYC can be found on Airbnb and CouchSurfing.
For more information about Brooklyn and NYC transportation, including recommended apps and web sites, see our NYC Info page.