Who needs to know how to write a will? Anyone who has a child or owns a home -- even if they don’t have significant assets. It used to be only a lawyer knew how to write a will, and you had to hire one and pay for expensive meetings with them. But now there are many alternatives on the Web, and some of them take less than an hour from start to finish and can cost less than $100. Here’s some of the possibilities that show you how to write a will.