Here are some resources you may find useful  to help manage business finances :

Receipt Bank

http://www.receipt-bank.com/

A very useful app that allows you to photograph all of your receipts using your phone and have them uploaded to a server where they are remotely analysed and the data is then inserted to a file that you can review and send to your book keeper . This app has transformed my life!!

Sage Accounts

Accounting software - very popular with accountants i and book keepers in the UK

http://www.sage.com/

XERO

Online accounting software, I've switched to this for my Aussie business and it's incredible. Very easy to see your P&L at a moments notice plus what cash is available including who owes you money and what your current liabilities are

 

UK version

 

Kashflow

Another accounting software solution

http://www.kashflow.com/

 

Sage Pay

http://www.sagepay.co.uk/

A solution to help you take payments online, over the phone or face to face using credit cards.  Sagepay is the payment process or and you need to tie that into a merchant account.

Authorize.net

Another Payment authorisation company - They have a useful video that explains how credit card payments work

http://www.authorize.net/

Global Payments

https://www.globalpaymentsinc.com/

Worldpay

http://www.worldpay.com/uk

Are  both merchant accounts that allows you to accept credit cards.  Setting up a merchant account is not easy! It is a form of credit and so expect a lot of questions  when you set up your account.

Paypal

A very popular method of accepting payment if you do not have  a credit card merchant account.

https://www.paypal.com

XE.com

This gives live foreign exchange rates and is a useful reference when working with international clients.

http://www.xe.com/