If your rental is 'exclusive' i.e. no bills are included, you'll probably need to get in touch with the water, gas, and electric companies yourself to get registered. You can call them, but much of it can be done online. Click here for more info on getting connected in the Netherlands.
As soon as you move into your apartment, you should arrange for internet access since it can take a long time for them to turn on it on (up to 6 weeks!). There are many cell phone companies in the Netherlands, and in Leiden most of their stores are on Haarlemmerstraat. Television* and landline calls can be included as part of your internet package with many companies. To start a contract with any of these companies, you'll first need a bank account number and address. Click here for more info on getting connected in the Netherlands.
*Some expats might also be pleased to know that BB1 and BBC2 are fully available in the Netherlands!
Depending on the area you choose to live there are two different ways to dispose of your rubbish. You can leave it out the night before the collector truck passes or you have to take it to special spots distributed around your area. For recycling you have to find a recycling spot (usually near the spot where you drop your rubbish). Here is the official link to the Rubbish policy in Leiden, where you can find out to which area you belong Garbage bags and everything related to waste in leiden Waste
Occupants are liable for paying taxes to the council. Details for Leiden can be found here.