I've been doing it for the past 10 years. Caller has hit the nail on the head mostly.
Your daughter should ask for a shorthold assured tenancy. The lease may be for a year, but it's effectively split into two 6 month periods. Neither the tenant nor landlord can serve notice until the first 6 months is up unless there's a major breach of contract. After that, notice can be served at any time. Notice periods are normally one month for the tenants, two months for the landlord. The shorthold assured tenancy protects the landlord against the tenants claiming squatters' rights.
Will your daughter be resident in the UK when she rents? If not, then she should apply for Non Resident Landlord Living Abroad Status. This is easily obtainable. The office is in Bootle, I think. The agents may insist on that anyway. This means that tax is not deducted by the agents. Your daughter does an annual tax return and pays whatever is due then. There's loads you can write off against tax - agents' fees, interest on mortgage and money spent on maintenance, 10% wear and tear. Tax liability should not be very onerous. Don't know the full situation if your daughter's residing in the UK.
Caller's right about the deposit. My tenants pay 6 weeks rent as a deposit. This now, by law, must be held by The Tenancy Deposit Scheme. They arbitrate on any disputes at the end of the tenancy. Their services are free. They make their money from the interest earned from all the deposits.
http://www.direct.gov.uk/en/TenancyDeposit/index.htm
Don't believe the time frame for resolving matters - I think they hope for 28 days. I'm going through this at the moment and it's taken 6 months for me to find out that I need to sign a consent form!!!! That's being sent to me. I'll be better able to advise on the service when the thing's finally resolved. There's almost 2,000 pounds tied up with them at the moment and I'm claiming most of it back.
It's the landlord's duty to maintain the structure of the premises and to ensure that all electrical and gas appliances are safe. She'll need to pay for safety certificates for this. Also that all furnishings comply with fire regulations.
Agent's fees can vary, so it's worth shopping around. I pay 10% for letting (finder's fee) and 6% for full management. You might be able to get less, but I'm generally happy with my agents and trying to change them from over here would be a nightmare. The 10% letting fee is paid quarterly in advance, but that may just be my agents. Don't know if others do it.
Can't think of anything else major at the moment. As Caller says, when your daughter decides on an agent, read the T&C's carefully. If there's anything you're not sure about, let me know and I'll compare to what I have and am happy to advise from there.