Can anybody please provide me link from where I can subscribe to alerts for international conferences, seminar, workshop etc or postdoc positions ? This could be very useful for me as I generally miss important conferences/seminars/workshops.
There are several sources I get information from:
Mailing list: See if you can find a mailing list specific to your area. Ask your advisor and colleagues about them.
Friends and colleagues in the field.
Word of mouth at other conferences: Ask participants about their favorite conferences & workshops.
Invitation emails of various kinds.
The academic sub-twitterverse
Wiki CFP: http://www.wikicfp.com/cfp/
Note that there are many conference/workshops that are not worth going to. And some of them are right out scams. I've read a number of horror stories about them (e.g. https://scholarlyoa.com/tag/predatory-conferences/). I suggest you choose carefully.
There are plenty of such services, for instance:
- Europe Conference
and I am sure you can find many more. I tend to be cautious with those, and trust a little more those maintained by individual, universities and academic associations. If they do not have mailing lists, you can subscribe to services of website content changes.
As for post-docs positions, they might be much less centralized.