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

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 does not go into opposition in 2008