Hi Bream
That's a really good question. There are a few simple rules to investment:
1. Don't invest in anything that you don't understand.
2. If it sounds too good to be true, it probably is. Walk away.
3. Diversify your investment portfolio. Whilst you'll reduce your chances of a big return on one investment, you'll reduce the risk of making a significant loss.
BigJohn is right with respect to paying down debt - in a low interest environment, this is a very effective way of improving your situation.
Make the best use that you can of tax breaks, for example cash and equity ISAs. Take out a pension (if you don't already have one), as your contributions are taken from your gross income (before tax), rather than your net income (after tax).
Work out what you're saving money for, and what your time horizon is (you mention kid's education and retirement, which are good reasons for saving!). In general, equities (stocks and shares) outperform other forms of investment in the long term BUT there are risks that you could make a loss if the market crashes.
Remember also that much of the long term gain from equities comes from reinvesting the dividend income, rather than from increases in the share price.
Motley Fool website & books are good and come recommended. Most respectable newspapers carry a personal finance section that should get you up to speed on the lingo. Investors' Chronicle magazine is available monthly in newsagents. If you want financial market data (share prices, historic info on dividends etc), http://www.iii.co.uk can provide this free (you have to register, but it's been fairly painless in my experience).
Feel free to PM me if you'd like to discuss this further.
Good luck!