Here's some ideas on how to plan your trip and where to go to [grouped together accordingly for easier navigation -- which places are near to each other, etc etc]
HISTORIC A:
Mount Fortress [Opens at 8am]
Macau Museum [opens at 10am; entrance fee around 10MOP, i think?]
St Paul's Ruins [Open 24/7]
Musem of Sacred Art & Crypt [behind St. Paul's ruins] -- 10AM; Free of Charge!
Na Tcha Temple [8AM] --> teeny tiny temple located beside St. Paul's Ruins
Old City Walls --> Very near Na Tcha temple. Not entirely tourist-worthy but might as well drop by while you're near the area
**around 5-10 minutes walk from St Paul's Cathedral are**
St Anthony's Church [opens 730AM]
Protestant Cemetery [opens 9AM] --> teeny tiny cemetery, first I thought it would overwhelm me with the size but not quite :)
Camoes Square
Camoes Garden [930AM]
HISTORIC B:
Cathedral Square
Cathedral [730AM]
Lou Kau Mansion [9AM]
Holy House of Mercy [10AM; closed on Sundays]
Senado Square
St Dominic's Square
St Dominic's Church [10AM]
Museum of Sacred Arts [right beside St Dominic's Church. No entrance fee but feel free to give donations! It's four floors of Catholic relics]
Sam Kai Vun Temple -- old temple.
HISTORIC C:
Macau Tourism Office [Lol this isn't historic but worth dropping by there to get some maps & other flyers that you would need for the trip.]
General Post Office -- quaint building
Leal Senado [Open from 9AM onwards; closed on Mondays] -- worth taking photos in the garden & the staircase!
St. Augustine's Church
St. Augustine's Square
Dom Pedro V Theatre
Robert To Hung Library [open 10AM onwards]
St. Joseph's Seminary & Church
St. Lawrence's Church
HISTORIC D:
Mandarin House -- loved this place! It's huge!
Lilau Square [teeny tiny square]
Moorish Barracks [Open from 9Am-6PM]
A-Ma Temple [Open 9AM-6PM]
Macau Maritime Museum [Entrance fee: 10MOP]
Penha Church/Penha Hill [Love the views in Penha hill! Church is also gorgeous! You could see this church from the island and is a breath of fresh air compared to the other churches in Macau]
Macau Tower [entrance fee: 100 MOP --> engage in the sky jump, bungee jump or sky walk x if you dare.. and if you've got the funds, of course]
HISTORIC E:
Guia Hill Municipal Park [Ride the cable car!! So cheap, it's a short line but FUN!]
Guia Fortress --> lighthouse & the church are a must see!!
Lau Lim Leoc Garden
St. Michael's Cemetery
Orient Arch
St. Lazarus Church
Tourism Activities Centre [Grand Prix Museum & Wine Museum]
Vasco de Gama Garden
Tap Seac Gallery
CASINO 1:
Wynn [catch the fountain show, the Tree of Prosperity & the dragon show!!]
Casino Lisboa
Grand Lisboa -- love the pineapple shape of this casino and hotel!
Worth walking around the street and getting photos with the amazing lights of these casinos at night
CASINO/SIGHT SEE 2:
Sands
Fisherman's Wharf [great place, but I was surprised that this place is not teeming with tourists! Just across from the Sands casino]
Lotus Flower in Full Bloom
Jai Alai Casino
TOUR A: [Optional, if you guys have more time to spend in Macau]
Lin Ze Xu Museum
Mong Ha Fortress
Mong Ha Park
Red Market
Mantanha Russa Garden
Islamic Mosque & Cemetery
Kun Lam Temple
Communications Museum
TOUR B:
Barrier Gate
Sun Yat Sen Park
TOUR C:
Handover gifts museum of Macau
Macau Cultural Centre
Macau Art Museum
Macau Science Museum
COLOANE:
Hac Sa Park & Beach
Coloane Village: President A.R. Earnes Square, Church of St Francis Xavier, Tin Hau Temple, Tam kung Temple
Museum of Nature & Agriculture
Seac Pai Van Park
Arboretum
Coloane Park
Alto de Coloane Park
A-Ma Cultural Village
A-Ma Statue [GOLD!!]
TAIPA:
Kun Lam Rock
Four-Faced Buddha [seen a four-faced buddha in HK before, in Repulse Bay, but idk how big this Buddha is]
Macau Stadium & Olympic Centre
Taipa Village: Taipa Houses Museum
Ka Sin Tong Temple, Our Lady of Carmel Church, Municipal Garden, Tin Hau Temple & Pak Tai Temple
COTAI STRIP: [mostly casinos]
Venetian [do watch the shows and my post about the venetian! =) ]
Hard Rock Hotel [I'm loving the memorabilia in this hotel!]
City of Dreams
Four Seasons [there's a passageway from the Venetian to the Four Seasons]
And that's it! Any questions, let me know =)