I have to be totall honest Dee, and hope you won't be offended, but I WOULDN'T do it... I don't feel that I'd have enough experience to 'run' a yard now, I know I wouldn't have had when I'd only had a horse for a couple of years.
I also think there are lots of other things to consider before you do make a decision...
If you're going to have 'liveries' (assuming the owner of the land allows you to 'sub let')....
.... are they going to pay? If so, what about tax implications?
...are you going to be insured? If not what happens if.....(insert horror situation of your choice where someone elses horse gets injured or killed and it's 'your' fault cause it was 'your' fence/contractor in a tractor/dog..)
...What are your expectations of your liveries going to be? All DIY? I assume so as you won't be making this your 'job', in which case, what happens when one or other doesn't 'do' their horse, or their share of the poo picking?
....How are you going to 'choose' your liveries? Is it going to be strictly 'friends' (great way to fall out with friends, becoming their YO!) or are you going to have to accept other folk too in order to make ends meet? What if you don't get on with them? Or two of your liveries don't get along? How are you going to feel about 'evicting' people with their horses?
.... What are your 'boundaries' going to be regarding use of the land/stables? Is it going to be OK for someone to hoon their heavyweight cob round your 'schooling bit' in wet weather and churn it up? OK to leave an obviously distressed horse in alone because it's overweight/got a show next day/owner can't be bothered to groom mud off if it goes out and rolls? OK to park a lorry/trailer/boyfriends quad bike on the land?
...Worming programme? How are you going to ensure that all the horses are wormed to YOUR satisfaction?
...Innoculations- will you insist that all horses innoculations are up to date?
...What about yard rules? Children allowed? Only accompanied? Dogs allowed? Use your own tools or have communal ones? Storage for tack, feed, rugs etc etc etc.
Also, how is the family that own the land and presumably from what you've said, live nearby or on it, going to cope with liveries coming and going, farriers/vets/dentists/feed merchants/ hay deliveries/ etc turning up, Horses to-ing and fro-ing etc etc?
I'm sure by now you are raising your eyebrows at good old 'the cup is half EMPTY' Claire... but the reality is that all these things will have to be taken into account, along with a million more... so please, think very hard before taking on such a huge commitment.... I'd hate to see your dream turn into a nightmare that spoils your appreciation of your boy and your 'leisure' time (which will become more like work than work!).