I'll walk you through what I do and maybe it will work for you.
#1 - I start by checking out my "Cathy Duffy Bible" from the library!
You can also check out her website http://cathyduffyreviews.com/
This book was such a life saver my first year homeschooling. Since I'm an eclectic homeschooler, every year I go back to the book to see what things I may have missed in the past.
#2 - I talk to other homeschoolers, people I know. I always ask two questions, What did you like about the curriculum and what didn't you like about the curriculum? I've learned what one person dislikes about something may be what I love about it. Since I not only know the parents, but I also know their kids, it helps to see if our children have similar strengths and weaknesses.
#3 - I check out reviews online. I do not recommend this if it your first year homeschooling. After you have a year under your belt you are much more confident in weeding through reviews to see what is really helpful and what isn't.
#4 - Then I make a list of what all we will be using next year.
#5 - Last year my friend made an awesome spread sheet to show what she needed to buy at convention. I stole her idea and tweaked it to fit my shopping style. Here is one page of this years list:
#6 - I try to buy my curriculum used if possible. My favorite sites are Home School Classifieds & EBAY. My home school group also has a classified list on our web page. The group also share and sell curriculum once a year at our monthly meetings.
#7- Whatever I still need to get I purchase at the convention or online after we get home.
What tricks or tips do you have for picking or buying curriculum?