STC buses pull into the Goil Petrol Station (Pedu Junction), about 5km from the town centre. Buses from and to Accra (from Circle) (C5. 3hrs) and Takoradi (C3, 1hr) go twice a day. There is a daily bus to and from Kumasi (C5, 4hrs).
You can also take a trotro from Kaneshie Station in Accra to Cape Coast (8 GHC, as of June 2013) and Elmina (11 GHC, as of June 2013).
Taxi is the best way and is very cheap by Western standards. Especially shared taxis are very common in Cape Coast.
Hang out on the beautiful beach under the Palm trees and watch the locals pulling in fishing nets and traditional boats.
Like most historic sites in Ghana, taking pictures is allowed in the Elmina Slave Castle so long as you pay a few pesewas (about 50 cents) at the front desk. The money you spend is well worth it.
Take a Global Mamas workshop on Batiking, Ghanaian Cuisine, or Drumming/Dancing, or Traditional Headwrapping. 
Take Drumming lesson at the Temptation Art&craft shop, from Ceasar. 
If there is a game when you're there, go see the Cape Coast Dwarfs play a soccer match in the stadium. Entrance fee is C3 and it's worth it! The level of play on the pitch may not meet European standards, but the enthusiasm of the fans surpasses those standards easily. Practically all spectators sing along in support of their team, encouraged by drums and other musical instruments. Do yourself a favour though: don't bring any valuables. There is always a risk of pick pocketing in large crowds and you will be feeling uncomfortable with a camera around your neck or your wallet showing through the bulge in your pocket. Do bring some petty cash though, as you probably will want to by some water after a while sitting in the burning sun. Also, little baggies with peanuts and other snacks are being sold by women (and some children...) walking up and down the stands. It can be great fun, although you could be intimidated by a hint of aggression that hangs in the air, but not like hardliners among the fans of some European or South American teams. Intriguing fact though: In the end of the match, the referee is escorted off the field.
Eli Emma, a seamstress on Aboom Wells Road, makes high quality tailored clothes. Prices are approximately GHC50,00 (U$10,00) for a shirt.
During the tour of the Elmina Slave Castle, they bring you to a bookstore within the castle filled with reasonably priced books on the castle itself, slavery, important black leaders, and even some books on Ghanaian culture (the Ghanaian cookbook is worth a look). If you need more time to browse, return to this bookstore after the tour.
Commercial Road has many great booths for small gifts-- one in particular has beautiful jewelery and beads. This, along with other stands along the road, offers better prices than the tourist stores in the Castle, and supports local economy. For fix and buy a Djambè, is at the Temptations art&craft shop, close at the vegetarian restaurant.
The main street has many good eateries.
Cape Cafe on Commercial Road has great cheap food. With a friendly atmosphere, quick service, full bar, and a menu of both Western and Ghanaian food, it is a favorite of both tourists and locals.
Further along, just to the right of the fork in Commercial road (the crab monument), Ant's Rastafarian Health Food Store is a gem for vegetarians-- smoothies, veggie dishes, and even tofu are available there.
There is a restaurant inside the Elmina Slave Castle, but it's recommended that you eat elsewhere. The food is average, and you'll spend most of the meal swatting flies.
Walk in the alley way next to the right of Malcom. Then make your first right into the smaller alley. Then your first left past the fruit stand. And you will find a hidden local market. In here you'll find the best fou fou lady in town.
Excellent Outdoor Bar with traditional dancing and fire eating up the hill along the beach.
Hostels/Guest Houses towards the beach are good quality and some have lovely roof bars also.
Tro-Tro's can be caught in front of the GOIL station (just West of Pedu Junction) along the main Accra-Takoradi Road.
Intercity STC buses can also be caught from the same GOIL station. The ticket office is on the second floor of the building just next to GOIL to the left. There are several departures to Accra and other locations daily. Intercity STC