From what I understand is that first what we do is create an environment where everyone is equal in wealth, opportunity, and social status. For socialism to truly advance you need everyone working together to efficiently use all of the resources available, for this you must go beyond national stage and onto a world stage.

Once everyone is socialist, everyone would have to do 10-15hrs a week of work to do their part, then for the rest they get to do whatever they want, further education, follow their passion, have a family, anything. By this point we slowly start to automate more and more and reduce the hours of work per person more and more as less hours are needed. This would start with everyone working for 15hrs~ a week as a replacement for automation, then as people find ways to automate their jobs the hours would go down, hopefully eventually getting to the point where only a few hours each week/month are needed per person and the work they do is fairly easy.

Labor vouchers are a very good step in the transition to help people spread out resources, but I believe that the end goal is having even less than that. Where everyone gets access to everything, if something is created where there aren't enough for everyone then, the inventor and those who help creating it are the first to get access to their creation and then slowly overtime as more are made more people will get access to it if they desire. As for how you choose who gets it first, you would likely wish to start with the exceptional peoples of society, teachers, fire fighters, hard workers, scientists, doctors, etc. and then work your way down as to reward those who are doing great work. Labor vouchers or something similar may be needed to separate some supplies though especially where there are variations of things. (ie each person would most likely get a phone voucher which they could turn in for whatever phone they wished of the available choices.)

It's not like there aren't enough resources on the planet for everyone to be able to live a comfortable life, these resources are mostly just horded by those at the top in capitalism, unfortunately.

For planning I guess it would depend on what it is who would be planning it, but in each case it would preferably be the most qualified people who have a desire to work on the project, whether that be planning for distribution, a city, any 'government'/public work. There would have to be various things in place to make sure that should any plan be followed through no one gets hurt, oppressed, and no one gets treated unfairly (positively or negatively). Either way the planning would be given to those whom came up with the plan, have dealt with similar situations, and/or anyone else who has additional, useful, ideas on how to go about the project, as well as some experienced planners to help ensure nothing is overlooked. Since all of this would be done by people that are doing it because they believe in the project, and not for monetary or self gain outside of being able to use whatever they create, you would most likely get the best most passionate people for each job.