Best 5K to 10K training?

Hi!

So I started running a little more than 5 weeks ago, I've been doing the Couch to 5K program and running/walking 5-6 days a week with that. My first 5K is June 1st and I'm feeling pretty good about it so far.

I want to run a 10K on September 29, which gives me 4 months between running a 5K and running a 10K.

What's the best training program for going from a 5K to a 10K? Does anyone have any recommendations?

Thanks :)

Emily