Here are some steps I have written down.

Getting Started:
1) Login to your forum, go the admin panel
2) On the left menu you will a new link "fShops: Make Money" click on it
3) Read, scroll down, click on the "CLICK HERE" and you will be taken to CP's site. On there you will register a FREE shop and will write down the Shop ID you created (also write down the email/password you used in case you forget).
4) You can now come back to "fShops: Make Money" and enter your Shop ID and press on "Login to my fShop". This will give you the fShop's admin panel's password and the link to log on page. You can login, check it out, change the password, etc.

Now Start Creating Products:
5) Now you need to create graphics which will be attached to your products. You can do this in either photoshop or some other image editting software. I highly recommend using .PNG or .PSD or other lossless format for your images. I also recommend that you use the resolution of 300dpi, so that the image gets printed on the products with high quality.
6) After you created the image, go to CafePress.com and login to your account.
7) Click on 'Go To My Image Basket'
8) Click on the 'Upload New Image' button
9) Browse and select the image which you designed
10) Write some keywords if desired press DONE
11) You should now see that your image was uploaded successfully
12) Go to Shop Management
13) Click on 'Manage Sections & Products'
14) Click on 'Add 1 or more products'
15) Select the products you'd like to sell,
16) In the right section, click on 'Select an Image' and select what you uploaded
17) Click on 'Add These Products'
18) Then you just play around and make sure the image is positioned on the product nicely (sometimes you need to make the logo bigger/small to fit perfectly)
19) After you create your products, click on 'manage' and click on 'change storewide product prices'. Here, with one click, you will be able to add your markup to the products. Choose a markup so your products are reasonably priced. In general, I'd recommend $1-$5 markup. Let's say you set it @ $5, and you sell 10 products per month, you will be earning up to $40-50 per month.

after the products are created and showing, you can start importing them to your fShop.

Now let's start importing the products you created into your fShop:
20) Login to your forum's admin panel, click on 'fshops: Make Money'
21) At the bottom enter your 'ShopID' and press the button. It will give you the password to login to the fShop's admin panel. (if you haven't done this yet)
22) Login to fShop's admin panel, Click on ITEMS tab, then click on the 'Import CafePress products into fShops' link. The small window pops up, you enter here your ShopID and it will pull all your products from CP to fShops.
23) You start playing with categories, to make it easier for your customers to navigate your Fshop. Select which product you want to be shown in which Category & click on 'update item info'
24) Now, when you go to your shop (forum.#.forumer.com/shop/) and you should see your products.
25) The next step is to start tweaking your store. The design is customizable, especially since you have access to the templates' HTML. In fshop's admin click on 'Select or Preview a Template' here you can click on 'Edit Shop Template | Edit Detail Template' and make HTML changes. Just make sure not remove the items that placed in ## (e.g.: #items#, #pages# etc)

I think this info should get you started.
Let me know if you still have problems.