Here are a few suggestions you may consider in helping children learn to identify the letters of the alphabet:

The alphabet song: This is perhaps the most basic, but is very useful. Do sing the alphabet song often. Sing it slowly and distinctly. It will also help if you have a large alphabet chart and point out to each letter while you sing. If you can give all children letter cards in order (alphabet flashcards) they can even hold up each letter as it is sung.
For each letter you teach, bring models of the letter (you can make cut-outs of the letter in card-board) and pass around to all children. If possible, you can make many so that you can give one to each child. They can slowly build up a collection of the entire alphabet. Bring objects or models of common things that start with the letter you are teaching. For example: for B you can bring a ball, bat, banana, bun etc. Pass around these for all to see.
Find a child whose name starts with that letter. He or she can then say out, for instance "Hello, I am Arun. 'A' for 'Arun'" and so on. He can be the leader for that day.
Engage the children in a 'Hunt For The Letter' game. Ask children to look around the room and pick up all objects that start with any given letter.
Use lots of colouring pages as most children love to colour. The colouring pages should have letters in large sizes to colour. They may also have objects that begin with that letter.
Kindergarten Worksheets: Use worksheets to help children re-inforce basic concepts in a fun and interesting way.

You can download some printable worksheets here: www.stores.lulu.com/kindergartenworksheets

For more ideas on teaching the alphabet click here: www.hubpages.com/hub/Kindergarten-Activities-and-Worksheets

Disclaimer: The above article only represents the personal views of the author, who doesn't claim to be an expert in this field. This is in no way a substitute for professional advise. You should take advise from a qualified professional when required. The author disclaims specifically any responsibility for any action or decision taken on the basis of this article.