You do not say how long you have had the money, or if it is a significant amount in relation to your other assets. If you received it recently, and if it represents a large proportion of your assets, my initial advice would be to first get used to having it.
If you have a mortgage, pay that and any other debts off as a priority. Then start reading financial articles from serious newspapers, and from publications from Execution Only Brokers such as Seymour Sinclair and Hargreaves Landsdowne.
An initial consultation with an Independent Financial Adviser would not be a bad start. They should try and establish your short and long term aims, plus how risk averse you are, which will of course all depend on your age. 20 years ago that is how I started investing after inheriting the proceeds of a house sale. Initially I wanted growth, now income. Currently that initial sum has increased by a factor of 15, despite the crash of 2008. My investments are a mix of income and accumulation items, with income all reinvested. You however might wish to take the income and just leave the accumulation aspect of your investments to grow, then later turn them into income investments. You will also have to decide how actively you will wish to manage the investments.
Some of my investments are paying a income of 3.8% or more, and as they are within an ISA, there is no income tax liability. Also, unlike any property investment free of capital gain on increase in value, and no tax on rental income, or aggravation from tenants. Although the value of stock/share investments can go up or down.
I suspect any IFA would guide you towards Stock/Share ISAs utilising both you and your wife.s annual ISA Allowance of £20,000.00 each first, but spreading the investment across a wide range of investment vehicles, I think with your amount to be invested at least 5. (It is also possible to invest in Property via property based investment trusts/funds.) I would think they would also suggest stock/share investments for the balance which you could move into ISA based vehicles over the next few years.
I now have some Insurance Company based Investment Bonds, from which you can take 5% pa without any tax liability for 20 years, the Revenue consider it a return of capital rather than income. Ok the money is invested in Stock Market vehicles, but you can choose which industry section, and the final value may be more or less than the initial investment . BUT you will have had effectively a return of 5% for 20years! Again it all depends on what you want to achieve from your investments.
I have tried to be as objective as possible, but not being specific, it really does depend on your aims, and we all have differnt ones. We do not have children, you may have and may wish to pass money on to them and minimise IHT. Investments are really very personal.
Good luck.