1. There are a lot of different oils, waxes, and dry lubricants for your chain. Just ask at your local bike shop - they'll have all sorts from cheap to wallet-clenching expensive - and select an oil they recommend. No need for anything expensive; all my road bikes get treated with an oil that cost less than £10 for a decent sized bottle.

2. Regular maintenance - as above, check the tyres, drivetrain, brake cables and pads. With brakes the rule is if in doubt replace - a set of pads or a new cable is cheap, and if you're not sure about fitting them get your LBS to supply and fit.
Clean the drivetrain regularly - if you're commuting in bad weather it'll get dirty very quickly and a chain cleaning bath plus a set of brushes will get everything running quietly and smoothly with 15 minutes work.
If you've not got one already a chain breaker tool is worth carrying - I've only needed to use mine once but I was 20 miles from home. It's essential if your chain snaps and can be useful if your chain wraps around the crank.