have a butchers on detailersworld mate, lots of info and tips.

Main thing is you want the whole process to reduce the chance of adding swirls etc, washing with a mit with a two bucket method rather than a sponge to avoid dragging dirt across the paint.

Snow foams to drag the majority of the dirt off the car before you touch it.

Clay bars to remove ground in dirt that is hard to spot.

bug and tar spot removers to break down any nasties rather than scrubbing.

Also look at waxes or sealants to protect the paint, as polish is just that, polishing but not sealing.

Wax will last for ages so spending £15 on some is no big deal, same goes for a decent polish.

Key is making sure it is cleaned and prepped properly so when you do get the polish out the paint is super clean to avoid adding damage.