First - attend the keynotes! (And don't be late, it's not nice.)
Second - pick sessions that look interesting to you. There are always more than I can fit into my schedule! A few popular sessions will repeat, watch for those!
Third - don't miss the social activities: the Search Party! and the Partner Pavilion and the SPLing Bee. These are fun, plus great opportunities to meet people that you only know online!
Fourth - Have a Splunk question that's bugging you? Come hang out at the Query Bar or the Answers booth and let's talk about it. Don't leave without saying hello!
that's kind of why i left it up here--not really a better place, per se.
however, there's a Slack Chat instance where some folks are hanging out, and there's a channel there for discussing/planning stuff for .conf 2015--if you email pie at splunk dot com with your full name, company name, and the email address you'd like me to use, i will send you an invite. 🙂