Hi BlixYZ,
Bitbridge loads automatically in the background. You don't have to do anything other than what fitzj said, and I would only do that if you have problems.
One of the major gripes here about Bitbridge and Jbridge (It's an alternative to Bitbridge that gives you more options, but you have to buy it.) is the crashing.
Two things I recently discovered that has helped me tremendously is ... I located the Bitbridge.exe file and went in to it's properties by right clicking it, and did two things ...
1. Set it to Run As Administrator
2. Set it to run in XP Compatibility Mode.
Perfect Space Convolution Reverb is 32bit and has always given me headaches with crashing. I've been using it extensively in every project since I changed those two settings, just to see if I could make it crash, and I haven't been able to. Not once. I've also used some free older 32bit VST's that used to crash and I haven't had a single problem so far.
Not saying it won't happen eventually, but it has significantly reduced the problems I was having.
Oh ... another thing ... if you have installed 32bit VST's and they are not showing up ... make sure you have set the proper path to them in the Plug-In Manager.
Good luck.