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   Lib M    Lib     Cnc     Tau     Cap     Cap     Oph
 Feb   Sgr M    Oph     Cnc     Tau     Aqr     Cap     Oph
 Mar   Sgr M    Sgr     Cnc     Tau     Aqr     Cap     Ser
 Apr   Aqr M    Sgr     Cnc     Tau     Aqr     Cap     Ser
 May   Psc M    Cap     Cnc     Tau     Aqr     Cap     Oph
 Jun   Ari M    Cap     Cnc     Ori     Aqr     Cap     Oph
 Jul   Tau M    Aqr     Leo     Gem     Aqr     Cap     Oph
 Aug   Cnc O    Aqr     Leo     Gem     Aqr     Cap     Oph
 Sep   Leo O    Aqr     Leo     Gem     Aqr     Cap     Oph
 Oct   Vir E    Aqr     Leo     Gem     Aqr     Cap     Oph
 Nov   Lib E    Aqr     Leo     Gem     Aqr     Cap     Oph
 Dec   Sgr E    Aqr     Leo     Gem     Aqr     Cap     Oph

Venus Notes
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.

E means it is visible in the evening just after dusk.

M means it is visible in the morning just before dawn.

O means it is not visible because it is too close to the Sun, from our point of view.

Mars Notes
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 goes into opposition on Aug 29, 2003