Notify on a new bundle

go to reddit.com/r/gamedeals or reddit.com/r/gamedealsmeta

I have most of the major bundle sites liked on facebook, they usually post their new bundles on Facebook as soon as they are up.
Otherwise, you can use one of the many bundle/deal tracking sites out there, I use IndieKings

For Humble Bundle with BTA price changes, the best way to get the best price is waiting at the time they started.

Main HB is switch regularly each 2 weeks, starting new bundle every Wednesday (01.00 AM GMT+7)

Weekly WB is switch regularly each week, starting new bundle every Friday (01.00 AM GMT+7)

So, if you're living at US/Europe it should be released one day before (Tuesday & Thursday morning).

Any other service announce it later after.

http://www.epicbundle.com

Has all the bundles and all the free steam keys

try this http://isthereanydeal.com/ ..

browse sg forums or join some steam groups like indie kings (there are several that send out notifications of new bundles quite immediately, but i forgot about most when i left them because there was no need to be notified of every bundle 5 times).

Full Humble Bundles always start on Tuesdays at 7pm GMT (I know about the last bundle, but that was a special charity thing that didn't last 2 weeks and wasn't that great to begin with). So if there is no active bundle it's a good idea to check the site each week at that time. I don't think for other sites timing matters that much, Groupees usually has a fixed price, Indie Gala also has a fixed price and constantly some kind of 'Happy Hour' or something similar. Bundle Stars and Blink Bundle have a fixed price as well. Personally I don't think any of the other bundle sites are worth mentioning.

www.epicbundle.com/
this website gives you all info and when you join their steamgroup they spam you all day bout new bundles, freegames and hotdeals

There are various Bundle Tracker Steam Groups, they make a new announcement every time when a bundle goes online. If you are joined to more, the faster you will see new bundles. Also every bundle sites has their Official Steam Groups. Join those too. At least this is what I do, and checking my Activity Feed more times a day.