The positions specified are for the 1st day of the given month at about 9PM. This should apply to the whole month for all of the planets except perhaps Venus, which moves very quickly.
Month Venus Mars Jupiter Saturn Uranus Neptune Pluto Jan Sgr E Ari Lib Cnc Aqr Cap Ser Feb Sgr M Ari Lib Cnc Aqr Cap Ser Mar Sgr M Tau Lib Cnc Aqr Cap Ser Apr Cap M Tau Lib Cnc Aqr Cap Ser May Psc M Gem Lib Cnc Aqr Cap Ser Jun Ari M Cnc Lib Cnc Aqr Cap Ser Jul Tau M Cnc Lib Cnc Aqr Cap Ser Aug Gem M Leo Lib Cnc Aqr Cap Ser Sep Leo M Vir Lib Leo Aqr Cap Ser Oct Vir O Vir Lib Leo Aqr Cap Ser Nov Lib O Vir Lib Leo Aqr Cap Oph Dec Oph E Lib Lib Leo Aqr Cap Oph
Venus is only visible just before the Sun rises or just after it sets. The letter after Venus' constellation refers to when it is visible.
When a planet is on the opposite side of the sky from the Sun from our point of view, it is called opposition. When a planet is at opposition, it is usually at its closest point to the Earth. Since Venus and Mercury are inner planets, they can never be at opposition from our point of view. Mars typically goes into opposition every 25 to 26 months.
Mars does not go into opposition in 2006