OK, Straddles are a bit of fun. but you going to need a lot of capital to do them as they are undefined risk trades. I have a couple on now and each one is about US$2800-4000 in buying power required to keep them on.
You want to get about $5 in premium for the trade and the research i have seen says take profits early, anywhere from 25-33%. but dont be afraid to be more aggressive and you can see profit disappear quickly if the underlying moves. Also being aggressive with profits frees up you capital.
It is not a beginners strategy as you need to know what to do when it moves against you. An Iron Fly is a synthetic straddle with some wings to help define the risk and limit the capital required. And then you know how much can make and how much you can lose. You're not going to wake up with a $1500 loss on a product you only collected $500 on.
As for weeklies, IMHO, you have nuts in your head doing straddles, you may as well just head down to the casino. Calendars, butterflys and condors for weeklies. Check out Dan Sheridan's stuff on managing a 10K portfolio with weeklies. it is gold and cost all of $300 for the 3 week live course. he runs them out of webinars and you can participate. YOu can get the first lesson for free on YouTube.
I run my straddles from about 40-50 days out and i take profits as early as i can. i dont mind being assigned on one side and then i will sell more options against it until i make my money back.
Also a fan of selling the 30 delta strangle - good credit received and a little more wriggle room for a market i am asleep for 70% of the time.
Good luck.