Any ride less than an hour = nothing usually, unless it's baking hot, then just water.
Longer rides = water or "High5 Zero" or "SIS", or weak orange squash with a little salt added.
Very long rides = as above, but will eat food also (enrgy bars etc), and stop for cups of tea etc along way
It;s very much down to what you like and what you can tolerate when you're on the bike. In my younger days I used to swear by flat watered down cola, but now it just makes me want to heave. I tried a few different energy drinks to see which I liked the most, some of them just tasted horrible, whilst others would repeat on me or make me feel ill, so you just need to experiment and find which suit you best.
Post-ride I just drink the same stuff (this is one area I probably should look into more tbh), I have tried Maximuscle "Viper" recovery drink, but again I didn't really like the taste. Personally after a ride I think my favourite is a glass of chocolate milk and a banana (I sound like a big kid but it's actually quite good fuel)