DreamHost SSL Certificate & WP

Hi – I’m pretty new here so apologies if this has been asked / answered before. I did do a search and most of the posts are from 12 – 24 months ago.
I’m hosting through DreamHost and purchased through them a unique IP address and an SSL certificate. I have downloaded the WP HTTPS plugin but have no clue how to set it up (not good with code I’m afraid!).
If I check the ‘Force SSL Exclusively’ box (in the plugin settings) and then check the ‘Force SSL’ box on a page I can’t load the page and get a big scary message about safety and the ‘https’ part of the page url is crossed out.
Hoping someone might be able to help me out.
Many thanks in advance! Regards – Dorian Kelly http://www.modalmusic.biz