Perhaps you should get your client to more precisely define what's meant by "layout." It's not likely you're going to give your client what's expected if you're blindly diving into the job.
My general interpretation is often called a dummy layout, which as has been already described here: sample images, greeked text, client logos and color schemes. Generally, a loose composition to simulate what the final job will be. Essentially, designing the brochure without any live content so you and the client can discuss what you like and don't like about the design and hash out how to deliver what your client needs.
Be sure to use the client's actual logos. It's important for clients to feel the work you present is done just for them. Actually using their logos and other graphic elements to reinforce the client's design language strongly reinforces you recognize that.
It's also probably a bit of a tryout. Your client likely wants to see what you can do, if given the opportunity. In short, if your client doesn't like the comp, it provides a spot where the job can be stopped before more time, effort and expense is racked up to create an end product.
Please allow me step up on my soapbox. If right now you don't know what your client is looking for in preliminary work for the job, you need to get with said client and work out exactly what your client expects from you. If you don't know, and the client isn't telling you, there's room for great misunderstanding. At it's best, that'll turn out to be extra work/re-work to get everyone and everything on the same page(s). At its worst, it turns into pay disputes and damaged reputations. More design jobs go wrong through bad communication than any other cause. Any graphics pro here can share many/great tales of woe that started from misunderstandings of what was expected for a job.
Delivering what your client expects and wants is the key to a successful business relationship. Understanding what's expected at the start of the job will save you immeasurable time and expense down the road. The worst part is you won't be able to recognize how much it cost until after the job is finally done.
*steps off soapbox*
Hope this helps,
Randy