Spanking tends to be done for the sexual arousal and gratification of the receiver. It can cover anything, from a playful smack when walking next to your partner, to a spank during sex, to using a paddle or cane to fulfill a long held fantasy of the receiver. It tends to be administered onto a bare backside or legs and is particularly popular in relation to bondage, where the feeling of helplessness at the hands of a dominant heightens the arousal the receiver feels.
If you want to give someone a spanking you need to find their limits and find out how they want it to happen. Would they prefer many light hits, or a few hard ones? Are they comfortable with a spanking cane or paddle being used? Will it be part of a roleplay? Establish a safe word with the person you are spanking in case it gets too much. The spanker will need to ready their equipment, if they are using any. The cane, paddle, or other tool will need to be placed in the room where the spanking will happen, so that when the time comes it is within reach and the fun can begin.
For those wanting to receive a spanking, then there isn't a great deal of preparation needed. For some, spanking is something they enjoy so much they have appropriate equipment to help them carry out their spankings, or to receive a spanking on. There are items such as spanking tables, with rests in the right places to ensure the spankee is positioned correctly to receive a good round of six of the best. Others may have spank skirts, which are skirts with a gap at the back to allow easy access to the bum for spanking. If that is something you are interested in then it's all the preparation you'll need to do.
When you are receiving a spanking, remember the safe word. If it gets a bit much for you, you can use it to take a break or end the session. If not, simply enjoy the feeling of a warm hand on your bottom, or the smooth feel of a cane sliding up your leg before it comes down again with a crack on your backside.