Thinking of starting a store?
All that time you could be playing with LEGO, gone. Stock management, acquisition, sorting, storage, location, order fulfilment - does this stuff sound like fun? And it's not like there's a bunch of money to be made either - the market has been getting much more competitive lately, and the dollar return on time invested is terrible.
But if you're thinking of doing it to get rid of some stuff you've got left over, something as a community service, to recycle your bits back to others that can use them - go ahead! A small store ought not take up too much time, but be aware that from time to time you'll lose a day helping another AFOL out by swapping parts for their money.
When you start a store, think about storage. Consistency and process are important when you have 2.5m3 of stock. I decided that I needed consistency, so I used 48L storage tubs from a supplier that has carried that particular model for years - I buy more each month. 48L is about the limit of LEGO I can lift. Get tubs you can label, and change the labels of - inventories are dynamic. My tubs have wheels, so I can wheel a stack away from the wall, dismantle to get to the necessary tub, access the tub, reassemble and push the lot back to the wall.
Within my tubs I store parts in two sizes of bags, also from a supplier that has carried these particular products for years. The small zip-lock bags fit comfortably within the larger one. The larger ones are as tall as the 48L tubs. Various colours of a particular part go with the smaller bags, which then go in the larger bag.
Once I've parted out a set, the bags of parts are added to the tubs via ingestion bags - bags that have stock that hasn't been integrated into that tub yet. The effect of this is that I can add stock to my physical inventory relatively quickly, and find it relatively quickly (if it's not in the tub, it must be in the ingestion bag). Tubs can fully ingest their Lego during quiet times.
Some parts - tyres for example - are difficult/confusing to tell apart visually, so label the bags with the BL part number. Trans-whatever and Trans-neon-whatever have a similar problem.
Basically, this all comes down to the evolution of your storage system. Try to keep a few steps ahead on the evolutionary path.
We all have parting out accidents - check out BrickLink's ability to consolidate identical lots as a useful tool.