Best place to get good accomodation at reasonable rates is Little India. you have very good 4 star hotels such as park royal on kitchener road, golden village etc.

for travel, take the MRT. They are very fast, frequent and take you everywhere you want to go.

Singapore is such a small place you can walk to most places. Singapore is also the world's most pedestrian friendly city.

the latest attraction is the Universal studios on Sentosa island which is a great one day trip along with the other attractions on sentosa. Take the cable car from the Vivocity mall for a great experience.

Other must dos include:
Jurong bird park
Singapore zoo
Night safari (you can get a park hopper ticket which covers all these 3 attractions at a discounted price)
Singapore flyer (giant ferris wheel on the waterfront)
Fort canning: WW II museum, good fun
Science centre- kids will enjoy this

And of course malls.................hundreds of them.!!