How to ask for a pay raise that is deserved and needed from a boss that keeps piling the work?

I work@a small service stat./c-store.Began summer '07,($9.00phr.),w/15yrs.exp.The guy before me, didnt do the job,($8.00phr.),played on puter&smoked alot.Ive been fixing his(3 mo.emp.)mess since day1,+doing the present work.Boss has loaded me down w/more than6new/diff jobs to do,+what I already do.I was hired to be the Bookkeeper&Accts.Rec./Pay.,ans.the phone,take appts for the shop.Now I also;order parts,track labor hrs.for shop buy supplies&groceries for the store,(off time),pay bosses child suppt,run his/her personal errands,pay their bills,paperwork for new hires,complete inventory/cost of the store&shop,cover at the register,deposits to bank,(driving own car 20 mi.rnd.trip&/or on my lunch hr&pick up parts if in town.No raise yet/no benefits.He acts like Im joking when I hint/imply for a raise.He ignores&continues his work.Whats the best way to ask&for how much?We(employees) have no benefits&now I have to apply to state aid prog.to survive.Im FT.103hrs.last pay period.HELP, please.