Dan’s Particle Playground tutrial is great but it’ll fly over your head if your new to the plugin – it’s quite advanced stuff. For a newbie, take a look, instead, at my COW tutorial on Particle PLayland. It covers the use of different images for each particle.
As for changing the scale for a particle based on its lifespan, just use the Persistent property with a full-on white mapper and have the Affects property be such that scale increases with time. You can do this via expressions or simply keyframing the values.
I’m not at a comp now so hopefully there’s enough for you to get going or perhaps someone else can come in should you be tied up.
Cheers
RoRK
broadcastGEMs
customizable animated backdrops with Adobe After Effects project files