i will assume that you know how to program and that you are trying to plan a software engineering project which includes a few people,,
i would advise you read, two books both from addison wesley/
software project management in practice by pankai jalote
and second
addison wesley software architecture in practice 2nd edition
It is hard to answer in short words. For a designer, you need rich software development experiences. Also you need learn some software engineering methodogy. It is not easy.