Any number of methods
This slogan, used originally by an American reading scheme, sums up the way parents have taught children to read for generations. Adult and child share a simple picture book. First the adult reads, then the child is encouraged to join in. Finally, familiarity breeds memory-skills and confidence, and the child starts reading the text independently.
The technique can be successfully adapted for groups of beginner-readers using short texts (particularly rhyming or rhythmic ones). Poorer readers benefit from repeated hearing of the text, as first the teacher, then other children read sections of it while they follow in their books. Do not overdo it though - if you feel obliged to hear every child read every word, boredom will set in.
The method is most appropriate in the initial stages - once children have developed a feel for reading and some basic word-attack skills, they need opportunities to tackle print for themselves. But it also works with better readers on a short, more demanding text such as a poem, which might otherwise be above their reading level.
Guided reading, as recommended by the National Literacy Project, is demonstrated on the Office for Standards in Education video, 'Literacy Matters'. The children must be of similar ability, and the set of books chosen must be carefully matched to the group's reading level. There is preliminary discussion about the book - title, pictures, any aspects that create a useful context for reading - then the children begin, simultaneously, to read the text aloud. The teacher listens, tuning into individual children to note and guide their progress.
Given a really good stock of book-sets - so you can ensure a suitable match - and homogenous groups well tutored in the regime, this system has clear advantages. Two group sessions means 12 children tutored and "heard" in a literacy hour, all of them actively engaged throughout.
But with inadequate resources and less-than-homogenous groups, it could turn into a nasty exercise in plate-spinning. If the reading gets out of sync, and two or three children need guiding at the same time about different things, the teacher is in trouble. Success also depends on the teacher's mental makeup - some of us would be driven to distraction trying to tune into one reader among six against the background noise of a busy classroom.
This is the time-honoured technique of "reading round the group". Each child has a copy of the book, and everyone reads a set amount. All children benefit from following in their books as their peers read, and from listening in on any advice or help the teacher provides. All too often, though, the listening child loses his or her place and drifts off.
The obvious way to keep everyone on their toes is not to read religiously round the group, but to choose the next reader out of the blue. Another option is to divide the reading into smaller chunks - poems can be read a couplet at a time, for instance, or stories with plenty of direct speech can be divided among readers like a play.
I sometimes used to ask children to read just one sentence each round the group, which kept them all engaged while also directing their attention to sentence punctuation.
Group teaching of reading need not always be about hearing children read. Once children can read silently and with reasonable fluency, you can ask them to read the book (or a section of the book) in advance, and use the group session for discussing the story, vocabulary, characterisation, and so on.