In reply to Fluvial:
Philip is right. Your greatest ability to give money to your child will come from your salary, not investing. Try to remove any debt that reduces your salary.
Get rid of all of your debt. I assume you don't have credit card debt, but if you do then pay it off. the same with the mortgage, pay it off. You will be able to contribute much, much more to your child by paying off the mortgage earlier rather than through investing. Every bit of debt means money to the bank rather than to you.
After you have removed all debt, then make sure you have a 6 month emergency fund. Best to have the emergency money in a money market account.
After that invest in low-fee index funds. It is crucial that you chose low-fee funds. Fees can drastically reduce your investments over the long term. In the US we have Vanguard, which is by far the cheapest and best fund company. I am not sure about the UK.
Also, make sure you are utilizing all tax benefits for investing. If you were in the US I could help, but I have no knowledge of the UK.
Ignore the 'sky-is-falling' brigade. I have yet to hear any wothwhile investing advice from these people. If they are right, then it won't matter were your money goes. If they are wrong, then you have just lost any gains through investing.