No problem. PEPs are not actually around any more so unless you already have one then you wont need to worry about them. ISAs are the current government-backed savings plans and are promoted on the basis that the interest is tax-free. However, from April this year, Gordon Brown is cutting back tax benefits and for this reason, plus the fact that the stockmarket is still rather depressed, you may not want a maxi (stocks and shares) ISA.
Cash (mini) ISAs will not be affected by the changes to tax credit expected this April.
Key things to remember are not to invest when you have debts as the interest you make will almost always be out-stripped by the interest you owe. Secondly, if you think you may need to get your mitts on the money sooner rather than later then don't lock it away for too long. If you need to get at the cash before certain time limits are up, you are likely to find that you lose money through penalties.
Here is an earlier post which may help...(it also has info on different type sof savings accounts in case you want something easier to access)
Intelligent Finance and the Portman Building Society are both currently paying 4.60% on Cash ISAs.
There are a few savings accounts with special offers which top that right now but watch out in case they dip to low interest after the introductory offer ends. You can get 4.70% from Chelsea Building Society with its 60-day notice postal account. Northern Rock and Egg are offering 4.76% and 4.75% on their online accounts at the moment.