Best option would be to buy through andhraproperties.com You can get all services like legal scrutiny, valuation, supervising sale registration, safe dispatch of documents by courier etc. and in some cases like plots from an approved layout you can expect at least 3% discount.
However,if you opt to deal directly, follow these safety precautioins :
(i)     Ensure whether seller is the right owner of property. Ensure price is correct and try to negotiate.
(ii)    Once offer passes this stage check for liabilities, obtain non-encumbrance certificate from Registrar's Office.
(iii)   In case of buildings find out income, tenants. Rights given to tenants, or ask for vacant possession.
(iv)   Make payments only for vacant possession - unless you are satisfied with tenents.
(v)    In every property deal, insist on original documents. Copies initially and originals at the time of transfer of the
        title (Registration of the same)
(vi)   In case of a power of attorney holder confirm that the POA is not cancelled, modified or nullified in any way. Announce in News papers your intention to buy and invite objections. this clears you legally to takeover property..
(vii)  You or your representative must visit site or building in person.Legal opinion and buildings Valuation by good
        valuers is a must.
(viii) Check for vaastu and adherence to vaastu- if you believe in vaastu.
(ix)   Make payment only at the time of registration. and make 100% payment pending only by pay order/ D.D/ Cheque   and deduct any advance paid.
(x)    Never try to register at a lower price. This is illegal and goes against you in future valuations while selling or
        receiving compensation from insurance companies etc.
(xi)   Ask seller to be present while handing over of property to you after sale and Insist on vacant possession
(xii)  Erect a board informing that you are now the owner. All tenants should get into fresh agreements with you. If you
        have any pending advances or dues with the previous owner- either get them transferred to yourself or adjust
        in payments made to seller.
(xiii)  In case of plot / vacant land / agricultural land / fruit gardens, invest in a good fencing and erect a board
         announcing your ownership of land.
(xiv)   Regular check ups on property is essential to ensure trouble free ownership.

WHEN YOU DEAL DIRECTLY, ALL THESE POINTS HAVE TO BE BORNE IN MIND. IT IS ALWAYS BEST TO SEEK HELP FROM PROFESSIONALS WHO CAN DIRECT YOU AROUND STICKY SITUATIONS AND GUIDE YOU TO HAVE A TROUBLE FREE TRANSACTION.