PSA to All New Bricklink Buyers!!!
Use the Bricklink Wanted list(s). Buying brick can be cheap (or not) but shipping is expensive and adds up quick. I recommend putting everything you've ever wanted in a Want list. When you visit a store you can click on an item and at the top of the store in the Shop tab is the Wanted List button. If you click this button it will show you all the items in that store that appear on your wanted list. This feature maximizes the Lego you are trying to buy in a store while only paying shipping once. It will help you save lots of time searching and chasing after brick in multiple stores and paying lots of shipping. It's depressing to want a $1.00 item but end up paying 4X times that to ship it. Using the Wanted List button helps you get a lot more of the Lego you want but still pay the same shipping cost.
A wanted list can also help you organize what pieces you are looking for if you are buying for multiple sets / projects. I like to use the Remarks to remind myself for what set / minifigure I am buying the part for. These remarks show up when you used the Wanted List button so you can decide if you want that part from that buyer at that price. It will also tell you how many of that part you are looking for so you can determine if the seller has the quantity you are looking for.
And lastly the Wanted list is very powerful in helping you locate stores that have the part you are looking for. By selecting an item (or more than one; or even your whole Wanted list) you can select the Buy Button and Bricklink will pop-up all the stores that are currently selling your item. Then if you select Auto-select, Bricklink will automatically choose for you the store with the cheapest price with shipping.
There are lots of ways to play around with Wanted Lists and the buying features. I recommend trying different combinations to see what works for you. Good luck!