I went all out on Excel because I'm fascinated with numbers. I've got graphs, projections, adjustments for inflation/raises/spending habit changes, etc. I do it all out of fun. But I know many people detest the idea of knowing how much money they have/owe.
I think the most critical thing to start with is to know where your money is going. How can you possibly have a wise plan for expendable money if you haven't even determined how much expendable money you have? For me, I opened up Excel, made a bunch of headings (housing, utilities, food (eating at home), eating out, entertainment, cars, school, health, etc.) Put in as many categories as you think are important. Then with every penny spent, enter it into Excel that night. Yes, even if you put a nickel in a parking meter, record it. After a little bit of time (a couple of months), you'll know roughly where your money is going and you can use that to do all the rest of your financial planning.
Why take all that time? (1) It is less than a minute of work a day and (2) people are very dilusional about where their money goes. You won't believe the number of people who are blatantly wrong about their own spending habits. I see it all the time with people who claim to spend $100/month on food. Then after a little probing you find out they drink a Starbucks coffee each morning at a cost of $1500/year. I'm sorry, but that one drink a day exceeded their entire estimate for all food/drink consumption. If you are dilusional, you cannot have a wise financial plan.
Take your current expenses and add in a safety cushion. You may be healthy now, but you might not be healthy next year. You may be happy with a beater car now, but you might not be happy with it in 6 months. Thus, you have to err on the side of financial surplus and plan for the worst. Take your expense number and add in say 20% of hidden expenses. The rest of your money is what is really expendable.
Or is it? Are you truely saving enough for retirement (run a 10 minute online calculator once a year to answer that question)? Are you truely saving enough to meet your dreams (house, vacation, new car, etc)? Only after that can you say the excess money is expendable.
A few other things:
1) I assume since you know nothing of stocks, that you have no retirement savings. It is really wise to get on this early if you can at all afford to do so. When you are ready, post again on ATOT and many people can give you advice on where to start. I personally suggest (and buy myself) a variety of mutal funds covering the wide range of companies (small/big, value/growth, US/international). You can buy all that in a few minutes and you'll beat 95% of other investors who spend hours a day on stocks.
2) If you can control your spending get a credit card as soon as possible. Not having one is harming you greatly in ways you can't even imagine. If you can't control your spending, do NOT get one.
3) Don't forget to treat yourself. The best way to save money is NOT to become Scrooge - living a life of misery just to have a huge pile of money. No, reward yourself along the way. Just don't go overboard.
4) I think the best way to do it all is to practice delay. Buy that new car 6 months later (and get 6 more months of free use of your current car). Watch that great new move at the $1.50 place a month later instead of at the $8 movie theater. Buy that new video game 3 months later at $25 instead of $60. Wait one more week for each haircut and save $100 per year. Wait for the new toy to go on sale/rebate (watch the hot deals forum here) and get it at half the price over an impulse buy. Do all this and you can have your cake and eat it too.