There are a few You can trust but its always better to check with someone that uses the site already, be careful using Your master key, use mainly posting key, and if possible check with someone who already uses the service/page..

Steemconnect.com actually helps in connecting to other services with less risk, I can say that I feel a bit more secure using it, but still share Your feeling about security when using services without steemconnect, also You can check the small lock/info in Your browser address bar to check if site is verified (don't fall for phishing sites)

Maybe this post from @technerd888 explains better and I don't want to induce You in error, check it out and safe steemin' =Ð : On Sharing Keys and Passwords with SteemConnect: How Safe Is It?

..after that You can always check ↓↓↓ it might be of Your interest ;Þ