Using Planners to Plan a Hero
This part is useful before your first time playing, but especially in between play sessions. For example, for the month prior to playing again, I can re-plot out powers and enhancements to compensate for new rules or additional levels that I know I'll get on my lower characters.
It gives me a bit of a game plan for what to do when my account goes active again.
Mids Hero Planner
I've only just started using it and there's a small learning curve, but wow! The amount of info it gives you is awesome. Check out this pic for Jordan's build. She has massive defenses and I can see how I'm going to use my invention sets to buff her max HP and damage potential.
I don't know how you'd even manage to plan out a character anymore without a robust planner like this unless you planned to ignore invention enhancements entirely.
Suckerpunch's Online Planner
Lil Pip's Hero Planner
One great way to pick powers other than starting from one of the other characteristics is to use a character builder. Not only do they have full descriptions of all the powers, you get the data on the range, recharge rate, accuracy, etc.
There are a few available such as the one at www.warcry.com (mirrored at coh.stratics.com), but it's not my favorite.
I'm sure it has a bunch of nice features and can probably do everything that you need a planner to do, but there's a few things I don't like. For one, it's not as intuitive as the alternative. It also uses SO graphics for the Enhancements which is clever, but not as useful to the new player who won't see those for a long, long time. Lastly, I just don't like the way it looks.
Joe Chott's Hero Planner
It's sadly out of date, but it was the first one I used and I keep it here for historical purposes. I really like Joe Chott's Hero planner (hosted by coldfront).
It's easy to understand and has a nice interface, but best of all are the stamina and defense worksheets that show you the effect your powers have on each.