Three Documents: (1) Central Atom Quandary, (2) Chemistry Balloons Activity, and (3) Molecular Polarity PhET.
These three documents will help students understand how the bonding (and angles) between atoms are connected and arranged. The first and third document are from the PhET simulations from the University of Colorado (phet.colorado.edu). You will discover that the atoms bonded in the Building a Molecule help demonstrate when bonds form and when they repel, plus you can see a 3-d visual of the molecule. The Balloon activity helps explain the different bond angles, although I don't use balloons in the classroom anymore due to latex allergies. I use extra large Christmas tree ornaments and use this information for demonstrations to explain the bond angle.
Central Atom Quandary is a great simulation for students to understand how atoms will be arranged in a molecule. This document is modified from the PHet teacher documents at http://phet.colorado.edu/en/simulation/build-a-molecule.
The American Chemical Society presented this activity at a NSTA convention and it was great at showing why the bonds are at particular angles.
Source: American Chemical Society
This PhET simulation will help students determine if a molecule is polar or not. The document is taken from the http://phet.colorado.edu/ website teacher page. The molecular polarity simulation will help student understand the uneven distribution of charge is key in determining polarity.
Source: http://phet.colorado.edu from the teacher documents portion