Babyshower101.com is a good place to start when looking into supplies for baby showers. If they don't have the banner you are looking for you could try banners.com to make a custom banner for the party.
Baby shower banners vary in cost. The cost depends on how big you want the banner, how many colors are involved and the saturation of those colors. It also depends on the material.
One can find neutral baby shower ideas from many places. Some of the best sites where one can easily find shower cake ideas are baby shower, shower for life and many more.
Babyshower101.com has a great list of baby shower games to play. You can also find a list of fun games at parents.com/baby/shower/games/fun-baby-shower-games.
You can find baby shower ideas for girls at the following sites. Here are the sites I found for you to look at pinterest.com/kaje_ryon/it-is-a-girl-baby-shower-ideas/ ,pinterest.com/simly/girl-baby-shower-ideas/
You will find a great selection of baby shower favors at www.BabyShowerStuff.com.
You can find wonderful, affordable ideas for your sisters baby shower at the following websites..webbabyshower.com/ or pinterest.com/smilescm/baby-shower-decor-ideas-themes/
At this website, you can find lots of baby shower ideas, and how to throw them. If you need some products to go along with the baby shower, they are sold online at that website as well. http://pregnant.thebump.com/pregnancy/baby-showers.aspx
There are several options to find tasty baby shower recipes, but the best would be www.plan-the-perfect-baby-shower.com/baby-shower-food.html. They have great recipes that are tasty, yet easy.
One can find a cute baby shower cake ideas from sites like cutest baby shower ideas, Wilton, coolest birthday cakes and many more. one can also find baby shower cake ideas from recipe shows or from recipe sites.
www.favorfavorbaby.com has many unique baby shower favors to offer.
You can find baby shower ideas for a baby boy in different places. Books are a great reference, party stores, and even event planning services would provide ideas of plates around a baby shower theme for a baby boy.
You could find baby shower paper plates at party stores. You could even find them at big grocery outlet stores. Try to search for it on your computer also. Have fun! Be creative! Baby shower themes are fun.