If you have sawdust or wood chippings the compost heap is not the right place for them. As they very slowly rot down they will rob nitrogen, thereby slowing down the rotting down of the rest of the heap's components. You can use them as a weed-suppressing mulch on shrubberies and flower beds. Even better, mix them in a big heap with lots of grass clippings. After a year or so you will have a lovely mulch, far better than wood chips alone. I do the same with fallen leaves every autumn. You get superb leaf mould in one year, instead of two or three. I don't even bother to cover the heaps but I do turn them over occasionally. I got this idea from the estimable Bob Flowerdew on Gardeners' Question Time years ago. It works a treat.