You can sleep baby from the start in their cot or cot bed. Usually it would be installed in the parents bedroom for the early months and later in the babys room or nursery room. It is now recommended to sleep baby at the bottom of the cot which is known as the feet to foot position which helps to prevent baby from wriggling under the bedding and over heating. A solid end cot maybe best for this.
Most cots will have a drop side which allows easy access to baby and a two or three position adjustable base which you will have in its highest position until baby is able to pull or sit up by themselves. After this you must drop the base to its lowest position. Quality cots will usually include teething rail protectors which help protect the cot and prevent injury to young gums and mouths.
A cot is normally suitable from birth up to two or three years with standard internal dimensions of 120x60cm.