thinking about business plans is good, writing them down is better, and spending a week or 2 putting it all into a spreadsheet to give you a 5yr plan is the bare minimum you should do before you comit to anything at all.
when you do it be realistic with income and expenditure in your forecasts. and then halve your income and double your expenditure. will you still be making alot more in 5yrs time than you would working for someone else? almost everbody starts up wearing rose tinted specs, and ends up broke. be aware that you'll have less spare time, holidays etc and a whole bunch of stress so make sure its going to be worth it.
