You'll find differing opinions on this. Plenty of people go without a TP at all and have a great time. There are much fewer logistical concerns to plan for at DL compared to WDW. And many people live close enough and are fortunate enough to go to DL regularly so they don't feel the need for a TP.
I do make a plan, because for me I'd prefer to identify our intended activities and fit them all in beforehand. Its fun for me to plan and we never have to stand there saying "what do we do next". I find it easier to tell my kids what we're going to do and get them excited for it than to ask their opinion and wait for them to decide - or wait in line for 2 hours because they chose Peter Pan at 3pm on a Saturday when we should have done it already first thing on Tuesday. (DH did this with them at WDW and that's exactly what they picked. Luckily it has FP there, at DL it would have been a major point of melt down).
I use Touringplans.com because I like that I can customize personal plans that include meals, breaks, and shows. A lot of people here like RideMax for optimizing wait times. Books are another option but for me I prefer to edit based on guidance I get here and personal experience, so electronic works better.