The key to reading is phonics, start by working on alphabet recognition, upper and lower case. Once he knows those well, introduce the sounds to each letter. Repetition works best for my kids, it does not have to be a long time spent on it but it does have to be daily. Take a light hearted approach to it so he wont resist.

Read lots of books to him/her. Take him/her to the library regularly for story time and to check out lots of books. Let him/her see you reading.

the best way to teach a child to read is to read to them a lot. find books that they enjoy -- something they are particularly interested in, fiction or non-fiction -- and read to them whenever the chance comes up, certainly at least good half hour a day. Make it enjoyable and stress free. Just let them have a good time with it. If they are interested in learning to read (if not, just don't push it at all, 5 is still young to be interested and you will not get good results by forcing the issue) encourage them to look at books themselves. They can easily start with books they already know well, and read them to you.

 The best thing you can do for any child is to talk to them. Have a conversation. Instead of handing them a drink when you think they are thirsty, ask them what they need. Reading is another wonderful way of developing language skills as well as associating print with pictures.