I have no shares, or any investments for that matter, however, I do happen to know a little bit... not sure how much you know?
Historically, stocks and shares our perform any savings account over a long period of time. If you need the money in, say 5 years, it is very high risk. If you are investing for 20 years, its generally seen as lower risk (but still higher than other investments). If you need the money at a certain point in time - lets say you will both be retiring in 30 years, and want to have a regular income from savings. Invest now whatever your maximum is (if you are uncomfortable with 85% then I would risk it), then slowly move the money out, so in 25 years (5 years before retirement) you have no money in high risk stocks/shares, and all sitting in nice, high interest rate accounts - fixed for reasonable term (the term will depend on market at the time) or government gilts etc
Do you want to be hands on with buying/selling, or do you want to put it somewhere and wait?
Some institutions are now offering accounts where you pay an amount in each month to be invested. This lowers your risk of buying all the shares at the top of the market.
HOWEVER, Id be tempted by an overseas property if it is somewhere that I will use regularly. You will be saving money on holidays every year, can rent it out etc.
You may what to try the savings and investments board on moneysavingexpert.com Lots of very clever people on there