The town is very much the holiday destination for Morocco's more wealthy city dwellers. With long beaches and a more relaxed atmosphere, it makes a welcome relief to the hustle-and-bustle of the larger cities inland. The town's other economy is its fishing industry.
The town is famous for the remains of Portuguese buildings and the Cistern. Although these are fairly limited attractions. Even the most dedicated historian may find their interest waning after an hour.
There are many (3-5?) buses a day from Agadir to El Jadida.
From the north, there are also buses (howmany??? 2?) a day all the way from Rabat, through Casablanca.
Many buses arrive at night. You are likely to find your hostel or campsite closed at 3:30am. If you have sleeping bags or a tent ground sheet, sleeping on the beach is possible. You may wake up damp from the salt spray though.
ONCF  trains depart every 2 hours from Casablanca Port and Casablanca Voyageurs train stations. The trip is around 1 hour, 30 minutes.
El Jadida is quite spread out along the sea front. It probably takes an hour to walk from one end of the centre to the other.
Cité Portugaise - the Portuguese town from 16th century
Relax in one of the restaurants or cafes in the town. Especially if this is towards the end of your trip, as it is for many. You'll find this town far more chilled than Marrakech or Fez.
Experience true Moroccan city life without the hassle, noise and glaring social inequity of Casablanca. Expect not to be bothered by anyone.
A few more 'western-style' restaurants along sea front, north of town centre.
Mint tea is available at the massive cafe in the centre of town, down the main road from near the entrance to the Medina.
Campsite, The campsite is at the North East end of town, located about 5 minutes walk from the large roundabout near the sea.
Mazagan Beach Resort, ☎ +212 5 2338 8000 (firstname.lastname@example.org, fax: +212 5 2338 8003), . Mazagan Beach Resort is a 5 star hotel, set in 250 hectares of undeveloped land, at the center of the oasis, next to a 7 km long beach, with 500 rooms and suites.
Riad Harmonie, 5 Derb Moulay Ismail - 24010 El Jadida, ☎ +212 678 356 694 (email@example.com), . Riad Harmonie is a guesthouse run by a lovely French couple who live on the spot with their two kids. The riad was opened in 2011 so everything is new and fresh. This place has a cozy and very friendly atmosphere and the owners speak very good English. Located within 10 minutes of a slow walk to Cité Portugaise.