Let me start with a disclaimer: I'm writing this thinking of parents of children who are native Spanish speakers and attend bilingual school (English/Spanish) where one of their classes is Spelling.
When it comes to helping their kids learn, practice or study their Spelling words, the parents' own ability to speak English is not as key as their understanding of how the child should learn/practice/study.
An eager parent can do more harm than good and confuse the child by using study methods that differ greatly from the way the student has been learning in school, such as using excessive translation when translation is discouraged in the classroom or organizing words alphabetically when words are organized contextually in the book.
Teachers who understand this will usually help parents by giving them tips to help their kids when preparing for a weekly Spelling quiz or even for a Spelling Bee.
For non-bilingual parents, it is essential that teachers share resources to help the parent understand the Spelling words the child needs to practice. A quick visit to http://www.wordreference.com/ will help the parent look up the meaning of the word in the English-Spanish dictionary and hear the pronunciation of the word, in most cases in both American and British English variations. Teachers can therefore suggest this tool to parents.
The following simple steps can be suggested to parents as a study sequence for young children:
1. Ask the child to look at the word (in their book, notebook or a flashcard) and say it aloud. Haptic learners might benefit from using their finger to "underline" or trace the word.
2. Cover the word and ask the child to spell it. Now, this is tricky for non-bilingual parents. How will they know if the child is spelling the word correctly? One option is asking the child not to spell outloud, but rather to write down the word. In that case the parent can simply compare the written word to the one in the book or flashcard. But if the child is practicing for a Spelling Bee, then she will need to spell outloud. Teachers can recommend that parents use an online alphabet such as the one in http://www.learningplanet.com/act/fl/aact/index.asp to check that the child is using the right spelling and actually saying letter names correctly.
3. If the child spells the word correctly with confidence, the parent places a mark next to the word in the book or separates the flashcard into a separate pile, the "known" pile.
4. If the child spells the word correctly with some hesitation and self-correction, the parent places the word into a "needs practice" pile.
5. If the child spells the word incorrectly, the parent places the word into an "unknown" pile, but first guides the child to spell the word correctly by gently pointing out the error. Parent should ask the child, instead of telling her: "What is this letter called?" (pointing to the letter). "Can you spell the word again?" "What comes after 'm'?"
6. Subsequent rounds focus on words in the "needs practice" and "unknown" piles, moving words to the "known" pile when the child demonstrates sufficient confidence when correctly spelling the word.
7. To reinforce meaning, parents can ask the child to use the word in a sentence. If the parent is not bilingual, they can simply say something like: "That sounded very good, what does it mean?".
As teachers we should encourage parents to use a lot of praise when helping their kids with their schoolwork. A child who feels encouraged, relaxed and accepted will do better than one who feels anxious about making mistakes.
If there are any specific techniques or steps the teacher uses in class, those should be explained to parents so they can be used at home too. After all, both parents and teachers are interested in helping kids succeed.