Can't help with supermarket details but Linha Azul ( Blue line of A Onda which serves the Porto da Mos route) travels along the Avenida - the riverside road - adjacent to the town centre so you won't need to change buses. If you get off the bus at Portas de Portugal, near the Law Courts and Post Office buildings, you'll be only two or three minutes from Rua 25 Abril where many restaurants are situated ( but also check out the side and back streets where you'll often find better value). As you get to the top of the Rua 25 Abril, you'll see many of the bars popular with younger tourists.

Many thanks Sagres. Im hoping to pick up a Map of the town once we get there, or does anyone know of a site where I could get one?

You're most welcome. Downloadable maps of the town ( and loads of other useful stuff ) HERE

There's plenty supermarkets in Lagos, so don't worry.

There's a couple of huge one's Pingo Doce just up past the marina, (about the size of our Asda or Sainsbury's),
and lots of smaller one's dotted around the town.

Great site Sagres. It just about covers everything.