Not to be a dick but this is the exact kind of thing that a search engine is for, not asking people on a forum. Anyway, oz = 28.1g half = 14g quarter = 7g eighth = 3.5g A dime, at least that I know if, is just $10 worth of bud. Could be varying amounts depending on quality. Usually about a gram, but could be more if it's lower grade weed.
An ounce is ~28g so an 8th of that is ~3.5g A good tool to do quick conversions is google, just type what you need into the search like the example in this link: http://www.google.ca/search?hl=en&q=1oz+to+g&meta= /edit: damn you astro, too damned quick for me