for information running a limited company and your responsibilities as the director/shareholder.
Take a look here
for information on corporation tax. A company with profits up to £300,000 per annum pays corporation tax at 20%. In fact, from 1 April 2015, there will be a single rate of corporation tax regardless of the level of the profits it makes.
Your company will need to set up a PAYE scheme even it pays no salaries as the CIS tax is claimed through the PAYE system in priority to being offset against the corporation tax liability of the company. If there is no PAYE liability, all the CIS tax deductions your company has suffered will be repaid on request after the end of the tax year on 5 April. You can then use that to fund your corporation tax liability which will be payable nine months and one day after the end of the company's accounting period.
The company will also need to register with the CIS to avoid tax deductions at 30%. You can do that here
You should operate a seaprate bank account for the company. You can pay yourself wages and/or take dividends to live in by transferring money from the company bank account to your personal bank account. You can refund yourself from the company bank account for business expenses paid by you personally from your own funds or on your own credit or debit card. It would be preferable to avoid paying personal expenses from the company bank account.
If you take your income from the company in the form of dividends, there will be no NIC charges on those. You can read about how dividends are taxed here.
If I were you, I'd have an accountant do all the compliance work for you as it can be onerous and there are penalties for late submissions.
I hope this helps but let me know if you have any further questions.