A lot depends on the style of scrapbooks you are planning. My favourite purchases, the things I use all the time include;
Shaped cutters, I have built up a collection over time including fairly inexpensive scissors, and gadgets that were a little more expensive.
A range of adhesives. Acid free glues, sticky pads for a 3D look, double sided tape and masking tape for holing things temporarily.
Notion. Buttons from my daughters clothes. Bits from her birthday cards, leaflets from places we visited, as well as the pre made things you can buy like stickers and badges. I even have small bits of her artwork in there. Although I love the things you can buy for scrapbooking these are usually outside my pricerange, so think outside the box. Decorate pictures from Halloween with Autumn leaves, or pictures of pumpkins either drawn or cut from magazines. Remember if it comes into contact with your picture it must be acid and lignin free.
Depending again on the style, I will take a photo or two that I want to use for a page and look at my card stock. I am on a budget and it took me awhile to build it up, so I used to take the photos to the store to find my base cards. Now I have a small stash it's a lot easier.
Depending on if you are journalling, it's worth thinking about how you will do this. By computer, their are so many fonts available, or if you want to do it by hand, this make it more personal, even if your hand writing is as bad as mine. A couple of decent pens are invaluable. Again, do they need to be acid free.
The internet. There are so many online scrapbooks, that although I personally don't see the point of copying someone elses page, after all it's not the same photo, I do sometimes use it to get me thinking if I'm not getting anywhere with a layout.
I use a scrapbook that I can re-arrange. I never scrapbook in order. If I have a great idea for the Christmas layout, I wont worry about getting the Halloween one sorted as my heart and mind will not be with it. Some layouts come together straight away, others just don't get into the book. Be choosy, but remember this is a hand made book. Like your Children, (mine anyway), It takes over your life, and although it's not perfect you love them for what they are.
I hope this helps.
I don't know what shops and fairs you have near you, but they are a great place to try out products before buying, and a great source of inspiration.
Junerose.