I'm well on my way to with stevenage (PS if you value your life don't read on, as this will take many many seasons).
Firstly, most of what you read below can be worked out yourself or by reading these forums. My knowledge comes from both. And this is the way I am *working* on doing it. Notice the word working, I have put in alot of hours and still haven't got as far as you ask.
I found the best way was to sell my good players, yes you heard me right

Each year I would pick up as many players as I could on free, sometimes buying some also. Would never pick up anyone over 24. Would work out which ones are the best (PS you start with quite a few as Stevenage

) and put the price up to like 500k - 2.5mil depending on which player. Pick up about 5 - 6 coaches in first year also. Make sure you get ones with about 10 - 13 in the stats you are after (and as high as possible working with youngsters (not sure if this actually helps but I always look out for this). EG do a search for all goalkeeping coaches with over 13 gk training and then pick one with high working with youngsters. Also look for a coach that has high judging player abilities / potental and working with youngsters. This coach will be your player training overview goto man, he will give you pretty solid advice on which players to keep and which to get rid of. EG if he tells you so and so has not been in the side recently but has the potental to be a big star, then you play that player

.
Eventually someone will come along and buy your players, if you keep winning (and they are good). I sold two in my first year, a certain striker (for 1.5mil plus 25% of next sale) and a young midfielder (from under 18's *might have been a regen*). Got 1mil and 25% of next sale for him. This was enough for me to spend about 400-600k (for the start of next year) all up on transfers and keep me in the black for the next year. ohhhh, I ended up using the offer to clubs to sell after the last transfer window, cause I wanted to keep the players till end of season. I also never loan players unless it is to cover for an injury. This is important, cause you want your players to get experience (so you can sell them for more).
At the start of my second year when all the transfers went through I picked up about 40 players, yes thats right 40 players (most of these on free when contracts ran out, but I did buy a few and spent about 400k (which I mentioned earlier). PS look in the reserves at higher clubs for players with contracts running out and shortlist them (only under 24 years old, preferably about 20), then as soon as you can start signing them try and sign as many as possible. I sold a few of the other players on my list for little fees like 1k - 20k. But I made sure I held on to any I thought could make it. So I ended up with 60 players on my list, probably not a good idea (but the wage bill was only like 28k and I was allowed 24k so not too bad) I Was allowed high wages because I had about 2mil in the bank. (at this time I asked board for training facilities and they said yes). Had to buy about 5 more coaches at this stage cause the workload was too much for the ones I had.
About half way into the second year, I sold another 2 players (Only sold players who I had good cover for). Got 2mil plus 25% of next sale for one player and 1mil for another. Worked out what players I didn't think were going to make it (about 20

). I use the player training overview for this, to see what the coaches say. PS sometimes they say different things if you swap the players between reserves and first squad

. Ohh and use the coach who I told you about earlier. Your main task is to keep building up cash every year so you can update training and ground.
Once you make it to the championship (and stay there) it is all about waiting it out, slowly build up ground and training some more and then when you feel you are big enough, try win it and move up to the big time. I feel it is all about making it to this stage. Cause anyone can pick up a side from here and turn it into a powerhouse in about 3 - 4 seasons.
The most important thing is winning in your first year and second year. Now this all comes down to tactics. My first year I played pretty much a 4132 (with wingers). Back four set at defensive, little creativity and virtually no closing down (changing if the DL and DR make runs or not depending on who I was playing and their tactics. eg if someone tries a 424 on me I set the DL and DR to man mark and tight makring and no forward runs, and counter attack. Would play direct when in this situation also, pretty much played direct all the time, except against teams who would get numbers behind the ball. Had the best striker in the league and another with 20 pace and 20 acceleration so it was easy to beat the offensive teams, just set them two as target men and run onto ball for target supply.
My main problem came when playing the lower teams who would get numbers back. I usually would play my third striker in these situations, he would have good jumping and I would set him as target man and supply to head. Would always set DMC on defensive with little creativity and mixed closing down. Rest of team would have closing down always and most of the time would be attacking, mixed foward runs on them all, But the wingers who would have often. Up and slow the tempo and time wasting depending on how I was doing. ohhh and for my super star striker I would set him for max creativity.
Second year make sure the strikers you pick up have all good physical stats so they can jump and run and do everything you need of them. I got rid of all my strikers from the first year because of this flaw. PS it is ok to play one striker with say jumping 10 and one with say jumping 14, but dont play two with jumping 5 or something. Cause you will play teams who will sit back and your strikers pace will mean nothing. This only really goes for my formation cause I always use wingers, and there is nothing worse than getting in 20 crosses in a game only to be beaten in the air 20 times. Also for the second year I changed my tactics around a fair bit and played more of a passing game because I picked up players with high teamword, passing, creation skill, etc.
lol I was going to post some more but this has gone on long enough

eg need to get back to my game

If you have any questions let me know.
One last thing, when you make it to league one in third year try to just not go down while still sticking with the sell good players tactic. I probably could have won this my first year up but if I had of it would have been worse in the long run because money becomes a huge problem. Need to slow down for a season or 2 or 3 or 4 and build up some cashish

Ohh and keep an eye out when new managers take over clubs (they like to sell good players for cheap

)
PS Good luck