For finger strength I advise these books called 'Hanon - The Virtuoso Pianist' or 'Dohnanyi' (or something like that, it's in Russian). Practice the exercises everyday, slowly at first, and then raise the tempo of the metronome gradually, until you can play them up to speed perfectly. Don't be tempted to go too fast, as this either just makes your fingers too exhausted or you skip/slur notes, thus making fingers do unequal work.

Sight-reading, there is no 'quick' solution. It comes over time and with practice when you learn how to establish well known patterns of music, etc. In order to improve your sight-reading, you have to make sure you haqve a wide repertoire, and do not merely focus on exam pieces. 'Hours with the Masters' is quite a good set of books that start from about Grade 2 upwards (note that Volume 1 is Grade 2 and so on...) and provide plenty of music, much like the 'Classics to Modern' series, or you could you the Keyboard Anthology set too... And you could check out some books at the library too.

~Wobby~