this is what i use to watch what i spend/help me save, i cant upload .xls's so delete the .doc part of the extension
each week i allocate a certain amount for bills, food, transport and spare cash. they go in the left hand columns. at the end of each night when im at my comp i update what i spend, and look at the total im my bank account and make sure its round about the total i have in the available amount. or more realistically itll be once a week and i jsut keep my receipts.
bills are for bills and things like fixed regular costs. for eg my martial arts fees are about $25/week so that goes in there. food is for food, transport is for petrol/train tickets/car servicing etc and petty is what i sqaunder each week on whatever there is. it helps me know how much i can spend, for eg i may have $400 in my account but only $80 in my petty so ill only get out that much when i go out. similarly if i have $100 in petty and impulse buy $50 worth of books i dont worry about it. extras are for one off expenses, for instance i got a new job so had to go buy a crapload of clothes, and i moved house so had to buy shit like a mop and breadboard that are more or less one off extraordinary expenses.
the numbers arent fixed in stone. if im constantly short i look at if i need to make changes either in my spending or in how much i allocate myself.
i dont know my after tax income so i dont know how much i save. not as much as when i was at uni, but still probably about 20%.
when i was at uni id earn maybe $400 a week and give myself between $75 - $100 dollars a week to spend on "stuff", which included $20 for petrol and $25 for martial arts. it sounds kinda harsh but by watching what i spent my money on i could buy things i wanted more, so instead of wasting it on day to day crap i could buy turntables and a crapload of music, stuff thats important to me.
the ever present book reference "the richest man in babylon" by george clason. this was the first book i ever read on finance type stuff and i was about 16. every library on earth has it, its quite short and well worth a read, particularly if you're thinking about savings. even if you can save 10% and the amounts are small, its the mental discipline of saving you'll develop so when you earn more that 10% will be more.