I do not know how effective the following is for helping children learn the alphabet and later spelling. However, I can see how it could be fun for the children (dyslexic & non-dyslexic) thus they may learn a little easier.
Some groups have suggested that they have had some success allowing children to make each of the letters out of clay when first learning the alphabet. This is suppose to help the child develop a 3D mental image of each letter. Thus, making it easier for the child to remember which direction letters are suppose to go when writting them on paper. (ie does a lower case B look like d or b.)
The same princable is also used with the spelling of words allowing the student to make each letter of the word and then 'building' the word.
I would think that an example of the word or letter would be placed on the board or some other prodominate spot (at least when first learning the letters & words.)
Again I do not know how effective this really is ... however as I said above I can see how it would be fun for the students. AND it would allow time for the dyslexic students to 'see' the words spelled out rather than simply writting the word and moving on.