Especially, I like to view sections about sports, science and health.

[Rachel Adams]

Are "social networks" and "view" idiomatic? Can I start my sentence with "especially"?

I read news sites and social networks. Especially, I like to view sections about sports, science and health.

 

[Tarheel]

Try:

I read stuff on news sites and social networking sites. I especially like sports news, science news and health news.

You can use "stories" instead of "news" if you prefer.

 

[emsr2d2]

There's nothing wrong with your use of "social networks". In my opinion, it's more natural and common than "social networking sites". I would favour "particularly" over "especially" but the latter isn't wrong. I agree with Tarheel that the position of the word in post #1 doesn't work.

 

[Tdol]

Or In particular.