Your best bet is to send for a brochure from P&O, this will provide information regarding tipping, dress code and dining. Drinks prices are fairly reasonable, equal to, or slightly better than normal pub prices.
Regarding tours, it depends how confident you are in yourselves, tours can be expensive and can seem poor value but you are guaranteed to get back to the ship on time, independents can be left behind.
As to currency, you can either take Euros with you, or you can buy them on board.
If you want any further information, please get in touch.
You only tip at end of cruise,you pay for all your drinks,
there is money spent on ship you have account card which you pay at end of cruise,i believe you can Euros onboard but i took plenty.as for dress code it will tell you on your ticket.
If this is your first cruise you will love the oceana, this is our favourite ship out of all of them. We are going on it again this June - 3rd time. Tip at end, dress code always mentioned in your daily newsletter, dont do excursions too busy sun bathing!!! but by what I have heard some are best to do on your own, much cheaper. Food great, expect to put on loads of weight. Bay of Biscay can be rough but we have not experienced it as yet for this time of year.