Can someone recommend a good resource on budgeting and forecasting?

I am looking for some reference material on budgeting and forecasting for an SaaS-type business. Can someone please recommend a good book or blog article they found helpful in managing their own company? It would be especially useful to see some industry-relevant rules of thumb.

If you do not feel a budgeting process is necessary to successful operation of your business then please comment on what process you find useful when planning for expansion or calculating operating cash requirements. For example how do you answer questions like "can I afford to hire a new employee" or "how many customers do I need in order to break even"?

Budgets are critical for a successful operation. You need to know what it will take to make your product and have some idea how much your burn rate will be.

There is really no good budgeting software that I have seen. Usually, people just use spreadsheets. You can use Quickbooks but it's not as flexible as a spreadsheet.

As David mentions above, knowing the range of expenses is an excellent way to plan. The main reason companies go out of business is because they don't manage their burn rate tightly -- that management starts with a budget.

If you want a link to a post I did on this, just let me know. In it, I also have a sample spreadsheet template that I have used a lot.

UPDATE: Here is the post I was talking about: Cash Budgets. It has a bunch of links to other articles as well as an example spreadsheet.

I would make a spreadsheet, for example in Excel, were you indicate time intervals in the future (for example each month) on one axis and the parameter in question on the other. In your case this would be cash.

Then I would fill in various expenses that would fall in each month to see when you run out of cash. You could also indicate income, for example, dependent on the number of customers you have.

I am sure you could make this a lot more fancy, but I often like the way one can adapt spreadsheets to exactly what you need.

I suggest making a best case and worst case scenario (I suggest not making the middle case scenario as it will take away focus from the extremes), to get a clearer understanding of your future.