Teaching Your Child to Read With Letter Names and Letter Sounds
Before a child can learn to read, he or she must first learn at least some of the letters in the alphabet, their names, and the sounds that they represent. To be able to read, a child must be able to recognize the letters, know the sounds of the letters, and be able to quickly connect the sounds together to say the word. The question I get asked often is should you teach the letter name, letter sound, or teach both together at the same time?
Should You Teach Letter Names, Sounds, or Both Together?
Studies have shown that teaching a child alphabet names and sounds together produces the best results.
In fact, studies have found that there is little value in teaching preschoolers letter forms or letter sounds separately. This was indicated by an Australian study involving 76 preschool children. The children received 6 weeks of training in either letter awareness, phonemic awareness, or control tasks, and then received another 6 weeks of training in either letter-sound correspondence or control tasks. The study found that training in either phoneme or letter awareness assisted with learning of letter-sound correspondences, and that the phonemically trained children group had an advantage on recognition tasks. The study found that there is little value in training in letter form or letter sounds separately. 
So yes, we should teach letter names together with letter sounds.
Other studies have also determined that teaching the letter names and sounds together helped children learn.
58 preschool children were randomly assigned to receive instructions in letter names and sounds, letter sound only, or numbers (control group). The results of this study are consistent with past research results in that it found children receiving letter name and sound instruction were most likely to learn the sounds of letters whose names included cues to their sounds. 
Additional studies stated: "Typical U.S. children use their knowledge of letters' names to help learn the letters' sounds." 
"...knowing the letter names helps children learn basic letter-sound relation because most names contain the relevant sounds. Differences between children in the experimental and control groups indicated that letter-name knowledge had a significant impact on letter-sound learning. Furthermore, letters with names containing the relevant sound facilitated letter-sound learning." 
Teach Letter Name and Sound Together
As you can see, letter names and letter sounds should be taught together. A child should learn the name and the sound of the alphabet letters, where letters with names that contain the relevant sound helps to enhance the letter-sound learning. When teaching your child the alphabet, instead of simply teaching them the name or sound of the alphabet separately, teach them together like so:
"This is the letter A, and the letter A makes the /a/ sound." (note: the slashes // denote the sound letter "A" makes, and not its name).
I should point out here, however, is that the letter sound is far more important in teaching phonetic reading, and typically, after I've introduced the letter name and sound to my students, we work almost solely with just the letter sounds.
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Castles A, Coltheart M, Wilson K, Valpied J, Wedgwood J.
2. J Exp Child Psychol. 2010 Apr;105(4):324-44. Epub 2010 Jan 25.
Learning letter names and sounds: effects of instruction, letter type, and phonological processing skill.
Piasta SB, Wagner RK.
3. Cognition. 2008 Mar;106(3):1322-38. Epub 2007 Aug 9.
Which children benefit from letter names in learning letter sounds?
Treiman R, Pennington BF, Shriberg LD, Boada R.
4. J Exp Child Psychol. 2004 Jul;88(3):213-33.
Knowing letter names and learning letter sounds: a causal connection.