Spreadsheets are great, I made a few back when I started this. They require a lot of time to make and maintain(if you can't get one from somewhere) but they're much more efficient then queueing with TSM. However they are only a step on the way. After a few weeks of using them you will memorize the whole thing, at which point you won't need them anymore. I had like 5 different spreadsheets for different professions, now I don't use any, not even wowhead, TSM or the AH prices. There is no better way, then actually knowing your server's market, but there is no other way to do that, then starting the hard way.
If you don't have a BS yet, you should level one when you have free time. It is great. It is very server-dependent, but the most profitable profs(at least on my server) are ENCH-JC-INSCR-LW-BS-tailor-ALCH-ENGI. Actually thats all profs, I just made them ordered:) Mining&herba is useless, don't even try farming, you can get the same amount of money with 10 hours of farming, as you would with 1 hour of crafting/AH playing/ad-ing in trade.
Untill you have enough capital you should stick with the profitable scrolls that you can sell, otherwise you are gonna end up with a bunch of scrolls instead of a bunch of gold. When you have more gold then you can invest on products, you can start crafting the cheap ones too. That amount varies depending on what profs do you have and what businesses are you running. For you I'd guess around 150k. That is of course capital combined with the net worth of assets, which should be 50kg for you, maybe 60k if you bought that stock cheap. Later, if you level other profs. the amount will change, but by then you will get the hang of it. I usually have around 250k of investments up on alliance AH and around 500k-750k on horde when I recraft. Oh yeah, that reminds me, if you can set up a xfaction business, do so. It is also very server-dependent so check the other AH on your realm for prices AND traffic, but most likely it is worth it.
I am probably going to find some spreadsheets i can use now i clean up my enchanting market a bit. I am looking to finish leveling alchemy for transmutes on my JC DK and i also plan on leveling other professions and characters, but i have to spend money on the heirlooms i use first (i like fast leveling
). Is it a good idea to get gathering professions for leveling? I usually grab herbalore and mining for new characters to grab mats for when i powerlevel a profession on them or to sell to grab a little extra gold.