This link might answer many of your questions.
Black plastic is mentioned but research has shown that clear plastic is more effective.
This link suggests not using an herbicide.
Newspaper and cardboard work well as a base layer.
Many gardeners have had great success with mushroom compost
as a key soil ingredient.

Here is a link that might be useful: Raised Beds

That is a very nice booklet.

Be - you won't be growing much new in a raised bed until September as we are coming up on the hot, muggy, bug laden summer time. So, if it were me, I would start the bed and layer on the cardboard and newspaper first, then add good soil, peat, compost and plant sweet potatoes or peanuts in it for the summer time. With plans to really plant it out in September.

~dianne

The only problem I have with the mushroom compost is that my beds grow a lot of mushrooms now. They die in the sun for the most part, but there are a lot of them out every morning.

When using newspaper, you don't need to wait. It sounds like the instructions you read were for pure weed-smothering, not necessarily for starting a new bed. The soil you add to "raise" the bed will cover the newspaper, which will decompose without any further action from you.

What weeds are there? How much height are you planning to add? You may not even need a barrier, although it's so easy to spread paper before you start adding soil, I would definitely do it.

I'm not very familiar with the different types of weeds that grow here -- the only "weeds" that grew in my mother's lawn in VA were oak tree seedlings, clover, and dandelions. It looks like some sort of clover, some grass (that looks better than my actual lawn, in fact!), and some type of weed that grows very tall very fast with an almost woody stem and pointed leaves. The weeds here are much more stubborn than those up north, I must say!