What is plastering of wall?

Plastering is an art which takes time to master it. Yes you can plaster yourself but it will take you a lot of practice to get a good smooth finish. If you want to give it a go you will need a multi finish plaster for normal walls, PVA, an old paintbrush, a bucket for mixing plaster, a float (the rectangular tool to spread the plaster on the wall) and a tray to use with the float.

Once you buy all those bits then you need to mix the paster to a smooth mouse like consistency, PVA the walls before you start then begin plastering once the PVA becomes tacky to the touch. Normally the first coat of plaster will be applied quickly and does not have to be a perfect finish, then once this dries to a stage where you can place a finger print in the paster (not too sloppy or dried hard), then you add the second coat of plaster which will be the final finish.

If you only need to do a couple of walls I would recommend hiring a professional as its very difficult to get it right. Watch the professional and learn how its done before attempting it yourself.