Hi before I give some feedback I just wanted to say congratulations and good luck with your startup. It's a big step and fun long journey and i wish you well : )

Now some things that could be improved on.

First of all the landing page. You describe the product well, its a good hook but you also need some information about your company too on there such as:

One or two lines of text explaining what you do such as Manufacturer of Wireless I/O modules based in (state and country you live). If you have a question you can call us on [Sykpe, VOIP or a 2nd number (don't use your personal home phone number -unless you want to be spammed with business to business calls - and not mobile because it doesn't look professional)] or you can email us at sales(at)yourdomain.com. Just something simple that makes it feel friendly. Just look at say some of your rivals or even say Rackspace.com. Just pad out a little more.

Also another thing to think about is who are you selling your product too. Is it home hobbyist or wholesale? If its both think about having two separate websites or even different section eventually instead of trying to do both. One consumer friendly and the other towards wholesale.

Another thing with your landing page is the colours and theme. It doesn't look bad but this is where I hope you don't mind me saying it but you could do better too. When you have the money think about getting a designer for your brand (logo) and site. Its a lot I know when you start out and is expensive so take it slow and at baby steps.

Now an example of a direct retail to consumer site that isn't super sexy but practical is http://www.google.com/phone . Okay its different product but for a consumer site from the manufacturer its one way of doing it as Its clean and simple. You can never have too much white space or even take a look at http://www.apple.com/ main site and their store. There different ways of selling but are clean and attractive without feeling cold but don't just try and copy them use your own ideas like you have done so far.

On your product item page, to make the icons blend in, there's a quick way of making them feel apart of your site. If you download GIMP. Take a screenshot of your web page. Load it and your icons in gimp. Use the color picker tool and select your grey web page background, then on your icons use the magic wand tool to select the white space and then fill the area with the grey color you selected. Then upload, your done or making the whitespace transparant and saving it as Gif. A simple little hack that blends your icons in. Just don't save over the originals as you never know when you might need them.

Also your datasheet download was two clicks instead a simpler one. You know the less hoops people go through the quicker they can make a purchasing decision. but your Datasheet is impressive. Its clean and attractive and the graphics are good.

Instead of using the html tables, why don't you consider using some of the graphics in the datasheet instead?

Also another thing (yikes this sounds like a lot of feedback sorry) is the shopping cart doesn't feel sexy. On the store page, the text is small and the picture with number underneath then select from menu seems too many clicks compared to a simpler picture with just a add to cart button underneath.

Also another thing is you don't list any icons for how you pay such as is it paypal or google check out. Do you accept VISA etc Is there a security seal saying your site is safe to buy from (which is snake oil but is psychologically reassuring).

Also using Chrome on Linux the add to cart button didn't update the shopping cart for me and even though I added products to the cart (At least I think I did) it didn't update so I was unable to go through your buying experience.

Now there is easier way of fixing it, if you don't mind outsourcing your shopping cart to a 3rd party. If you use http://www.e-junkie.com/ with paypal and google checkout, then it solve some headaches for you so you can just concentrate on designing and building your modules then having to fix your site. I haven't personally used them but I know of them and how simple they are to install and use and take care of the buying experience. There is also http://www.shopify.com

Also I personally wouldn't use a forum starting out till you have a customer base because an empty forum doesn't look good. Think about using a simple blog to start out with and maybe disable comments so you don't have to worry about the 'empty comment syndrome' where it looks bare and not used much. Its just an idea after all then once you've been around for a while and have some customers add it again so they'll be more people.

Also a blog and twitter is handy for PR and Buzz. Think about say a separate blog for products with case studies and real life examples of using your products in the real world and how to's and one for electronics with say tips on making circuit boards, circuit design and stuff like that. The idea being is that helps put you yourself out there and as a trusted source. If you can provide good advice that people find useful than maybe what you make is good too and people might buy it. Using a blog to sell a product is one way of doing it.

Yikes, sorry for such a long post but I hope that you'll find some of it useful but its not gospel and use your own commonsense, judgement and take it with a pinch of salt : )

Edit: Typos/Small Corrections to make it more readable.