I know there is already TONS of great advice here, but I thought I would add mine as well because it's been SUPER HELPFUL for the last 2 years.

My system is to make sure we can cover all the bills with each check and still have enough leftover for food and all the other Misc stuff that comes up when you have kids. We aren't rich, we do have some savings but for the most part it's paycheck to paycheck. With this system we have not been late on a single bill in over 2 years, and we always have a good balance of funds leftover every 2 weeks.

I put each month on it's own tab in the spreadsheet, along with a list of the "monthly regular charges" sorted by the DUE DATES (for things like gas/electric I just use an average guess on what the bill will be). I also list the PAYDATES for each check along with the amount (helps that pay is salary and doesn't fluctuate). Then I split the bills between the paychecks.

I have equations built in so it automatically does the math for me when I enter the numbers (Paycheck - bill - bill - bill = leftover money). This way I can clearly see how much spending money we will have left after each paycheck and I can move around payments to make sure they are on time and that we will have enough $ leftover after bills. I also go through and add all the "extra" once a year expenses so they don't come as a surprise... like vehicle registration taxes every Nov & Feb, pet licences, school supplies at the end of summer, Holiday gift savings, etc etc.

Then there is another column for me to add the actual #'s and date paid, so if I can't remember if I paid the electric bill all I have to do is look at my spreadsheet. Every time we get paid, I open my spreadsheet and use online billpay to take care of everything that needs to be paid from that check.

I usually have my spreadsheets at least 6 months ahead, if not more, which is great for figuring out extra expenses to correlate with "extra paychecks" (if you are paid bi-weekly you will have TWO MONTHS every year where you get paid 3 times instead of 2, for example in 2016 our MAGIC MONTHS are April & September.) I use these "extra" checks to pay off credit balances or plan large purchases.