The most important thing you can do with your children in order to teach them is to play! Play is the best thing for teaching them anything, plus, the good thing is it is fun too!

Children learn so much from play and it is such an important foundation for later learning. They can still learn so much 'incidentally' by having time to play, explore, experience life and it is learning in a way that we are designed to. The problem is that when we begin to try to teach kids formally, we can over-rule the natural learning or even worse, undermine their natural love of learning and undermine their confidence.

A great quote I got from my mother who is a kindergarten teacher with 45+ years experience in early childhood development, sums it up (although I am not sure where it came from so cannot provide a reference)

"Children who are rushed into reading and writing too soon miss important steps in learning and may suffer later on because the lack the foundation the need for using language. Children who are taught to read in preschool may be able to sound out and recognize words but they may also have little understanding of what they are reading. If they haven't been given time to play, they won't have explored objects enough to know what words (like 'hard, harder hardest) mean."

So, that said, the best way to incorporate 'teaching' reading into play is to read to your children. You can use language which is wonderfully descriptive in daily life to open them up to as many variations in our language as possible, point out familiar letters such as the letter at the start of their name when it appears on words in their everyday life, answer their questions and describe things, describe things, describe things! Sing nursery rhymes and chant silly rhymes and songs. Immerse them in play with words such as storytelling, 'reading' signs along the road in the car and making the same signs at home with their play cars and train tracks and make shapes or patterns with magnetic letters on the fridge. Write letters (as in good old snail mail) with your children, even if they are just scribbles and send them off to family and friends making sure you get replies in the mail. The engagement of litricy skills in exciting things like mail and communication with people is really exciting for kids. Make your own story books with photos from your daily life such as "making porridge for breakfast" or "What I saw on the way to the park". Children love to see pictures of themselves and to see them in story and book form is a great way to engage them. Write down on their drawings what they describe so they get a grasp that those funny things you scribble are words and show them to other adults so that they can engage in the drawings and the stories that go with them. Help them recognise familiar things like their favourite cereal at the shops and recognise the words printed on it. Help them enjoy and further develop their innate love of learning through discovery.

That said, if your child does show interest in taking things further, go with it. Let your child lead you in the pace they are ready to learn. Children at this age are just born to learn when they are given the time and space to do so.

This will be, hands down, the best way to introduce your child to reading and will mean that when the time comes to formally learn it all, they will be engaged, ready, resilient and competent and much less likely to slip through the cracks.

Also having four boys under 4 I don't want them to miss out on the type of mental stimulation a mother of say two kids four years apart is going to get ... If that makes sense?
You know what, sounds like your boys will be fine as you are thinking about them, asking the questions and try to do the best by them. This is streets ahead of lots of kids. Doesn't matter about the number of kids or the closeness in age when you have a desire to do best by them. Quality not quantity! (well maybe quantity in regards to play )