You are best off going to money saving expert. I can give you a general summary though -
You (and your DH) can only put £3600 into an ISA each per year. That's a cash ISA. I wouldn't want to put money into shares right now unless you won't need it for at least 5-10 years. If you want to put it into shares then rather than pick individual shares it's better to use a tracker - and you have another £3600 each that you can invest tax-free in an ISA.
Premium bonds do not give a good rate of return unless you are incredibly lucky. You're better off with a savings account.
If you can be sure that you won't need the money in the next year then you can put it into bonds where you have to keep it in for 1 or 2 (or whatever) years. But there are severe penalties for taking the money out early (often you lose all the interest).
It's best to spread the money around several savings accounts to spread the risk. It's highly unlikely that a bank will go under, but if they do, only the first £35,000 is insured (i.e. you will only get the first £35,000 back). The website I linked above has details of all this and a list of the highest interest easy-access accounts.
One last point, if you don't work, then you can use your income tax allowance to save paying tax on some of the interest. If it's a large sum of money (and I'm guessing it is) then you should put it into your name, and then you can claim part of the tax back at the end of the financial year.
You can probably tell that this is something that I've thought about. We have a large deposit saved for a house, but we're holding off buying for now.