http://www.wwltv.com/video?id=105483253&sec=568112The most sought after species is the speckled trout and this time of year they're in transition from the outside to the inside. Since you'll have access to a boat I'd try fishing the bridges (Causeway, I-10, Hwy 11, you may also want to try the Train Trestle) with your choice of plastic or live bait. In the video you can see the carolina rig we use to fish live bait... also market bait (fresh shrimp) can be fished the same way. If you happen to catch any small croakers or white trout you might want to try cutting them up and fishing them on the bottom as well....fishing this way should land you some reds. The lake is brackish but saltier on the Eastern end where you intend to fish. Since the water is brackish you can catch an array of different species from catfish to sharks.
When it comes to tackle I've always used reels and rods similar to bass tackle except I don't use any made with magnesium. I prefer 6'6" to 7' medium action rods but use medium heavy action rods when targeting black drum and reds. As far as line goes I tend to stick with monofilament around 15lb test adjusting that according to what I'm pursuing. Some people swear by braid...I suggest you use whatever kind of line you have the most confidence in.
One of the most productive artificial baits I've seen is the Gulp! shrimp. You can rig it on a jighead and just allow the water depth and current to dictate what weight to use. Usually for me 1/4oz or 3/8oz is good enough. Just jig it on the bottom around the pilings making multiple casts to each...sometimes you'll catch a fish on the opposite side of a piling you didn't get a bite on.
Ask for advice once you get to Slidell especially if you visit a bait shop (Rigolets Marina is close to where you'll be) so you can find out the most recent information on what's the best location, technique, and particular lure to use for the species you're after.
Listen, have an enjoyable trip and if you have the time come back here and let me know how it went.