I used to get my kits at the hobby shops, but prices are much better on the internet. I got a small stash, but I decided I'm not going to get more kits until the ones I have are finished. As for colours, glue and supplies I prefer going to the shop.
Here are my favourite web dealers.
*Luckymodel.com. Pros: excellent service and prices, especially for newer kits, no minimum order. Some products have free shipping with registered mail and parcels can be tracked. Cons: the packages may take long to arrive depending on the situation at the post office in HK. Moreover, living in Italy makes me experience trouble sometimes because big packages are inspected at the customs, and there seems to be only one customs office in the whole country for package coming from Asia, so a parcel could take 3 days to reach Italy from HK, but will take 10 days from its arrival to be delivered to the final customer!
*Hannants. Pros: maybe the best and biggest stock of products around the web, no trouble with the customs (as far as you live in the EU). Cons: minimum order and higher prices.
*Modelimex.cz. Pros: friendly and helpful service, good stock of products, especially Eastern European brands. Cons: their payment system initially charges the maximum shipping charges but actually gets the requested amount. Weird!
*Modelhobbies.co.uk: tried only once for a small kit a couple of years ago, they stock a good selection of products. I read some negative comments about them but my kit arrived in a sturdy package with no problem after a week from the purchase.