Warsaw has a huge range of accommodation, from backpacker hostels to luxury boutique hotels, spread widely across the city centre. However, you'll get cheaper rates at places outside the centre in exchange for a short tram or metro ride.
Note that many Warsaw hotels are geared towards business travellers and are priced accordingly. Try to time your visit for a weekend, as many hotels offer discounted rates.
A short-term rental in a private apartment can be cheaper than a full-scale hotel; if you’re staying longer than a couple of days, it's an excellent option. Short-term rentals usually have one or two bedrooms (for up to four people), plus a small kitchen with a few handy appliances such as a toaster and a coffee maker, not to mention a washing machine, a handy solution to Poland's lack of laundromats. Since there’s no reception desk, you’ll usually have to phone in advance and set up a meeting place to get the keys. Normally you book online with a credit card or pay in cash on the spot.