Studio lighting advice?

Ok, so i'm new to studio lighting but am eager to get into portrait photography, i bought a couple strobe lights and i use a Nikon D5000, now i understand using the built in flash on my camera fires the strobe light to flash but does it have disadvatages using the pop up flash, would it be a good idea to buy a wireless trigger? Also i'm not 100% sure how they work, or am i gonna be fine just shooting with the camera flash. Any info on this subject would be great!

You didn't say, but I will assume that you have Nikon strobes. I do not think any other brands will work with the Nikon CLS. If you don't want to use the pop-up as a trigger, you have a couple of options. First of all, you can actually set the pop-up to "no flash" and it will still trigger the remote flashes. It does emit a very low power burst to trigger the other flashes, but it is all but invisible. The only time I found it to be a problem is when photographing glassware as it still makes a reflection from dead center. You could also buy a sync cord to attach to your hotshoe and use one of your strobes as the master by connecting it to the sync cord and the other strobe would be the remote. I use the Nikon SC-29 sync cord for this. You can also use the SC-28 and cords from third party manufacturers.

It seems a bit confusing when you first try the CLS, but just open the manual up and go through it step-by-step. Start by just putting one of your strobes out there somewhere and use the pop-up as a trigger. When you see the other flash go off the first time, you will have a feelign of amazement, but it's really quite simple once you put it into practice.

If you want to get what I consider to be the "bible" for Nikon CLS, pick up Joe McNally's "The Hot Shoe Diaries" and read it. The book starts with simple one-remote set-ups and move into increasing complex set-ups towards the end of the book.

Yes, the trigger would be a good idea. They work great, and operate sort of like a remote control device. The pop up flash being directed straight at the subject from the camera has a couple draw backs. One being it can sometimes cause that horrible red eye, another it tends to wash out shadows and highlights taking away some of the natural depth, contrast, beauty and form of the subject.
Lighting from angles gives better results. As an example one of my photography instructors years ago pointed out what he referred to as the Picasso Triangle. It is actually a gentle triangle of shadow created on the face from the nose due to lighting from one side of the subject. It is true without it a face looks flat.

Actually, that's Rembrandt lighting that creates the triangle.

I think the asker may mean that he was using the pop up flash to optically fire strobes instead of the Nikon commander system.

I would definitely get radio triggers. If the strobes you have do in fact fire optically, you can get away with one transmitter (on the camera) and one receiver (on the light), and let that light fire the other optically. Either way, don't use the on camera flash. That defeats part of the purpose of studio strobes in the first place.

There are many different kinds of radio triggers. Yongnuo makes some cheaper ones, Alien Bees have the CyberSyncs (you can use these on lights other than Alien Bees), Elinchrom Skyports, Pocket Wizards, RadioPoppers… The list goes on.

While the Yongnuos have good reviews, even among people here, I was damaged long ago by cheap triggers and won't give them another shot. I got two different sets, and they were horrible… And nothing screams unprofessional like your gear failing mid shoot… Not that I know ANYTHING about that…

If, however, you're just going to be doing some friends and family stuff… Save some dough and go for the Yongnuos. They're cheap, and recent reviews are good… And if they fail while you're shooting family you don't feel about an inch tall…