If you can find the constellation in the sky, then the indicated Planet will be within that constellation's boundry for that month.

Venus, Mars, Jupiter and Saturn are the only Planets that are easily visible to the naked eye.

Mars brightens noticably every 26 months (because it gets close to Earth), otherwise it is not bright like Venus, Jupiter and Saturn.
The next two times Mars is bright is January 29, 2010 and March 3, 2012.

Notice that Mercury and Venus are often in the same constellation as the Sun because these two planets orbit close to the Sun.